Feasibility, efficacy, and social validity of home-based storybook reading intervention for children with language impairment

Abstract

Purpose.

This study evaluated the feasibility, efficacy, and social validity of a parent-implemented intervention for promoting print knowledge in preschoolers with language impairment (LI).

Method.

This trial involved 62 children and their parents. Each dyad completed a 12-week intervention program. Parents in the treatment group mplemented print-focused reading sessions; parents in two comparison groups implemented sessions focused on either storybook pictures (picture-focused condition) or phonological concepts (sound-focused condition).

Results.

Many parents completed the program successfully, but attrition was high; 23% of families dropped out of the program. Children who remained in the treatment group demonstrated significantly greater gains on one of two measures of print knowledge compared to those in the picture-focused condition but not the sound-focused condition. Parents generally reported favorable impressions of the program, although several aspects of the program received higher ratings from parents in the print-focused group.

Conclusion.

Study results raise questions about the feasibility of home-based intervention for some families; future research that examines the characteristics of families which may affect completion are needed. The causal effects of print-focused reading sessions are promising for addressing children’s print-concept knowledge but not alphabet knowledge. Home-based reading intervention has considerable social validity as a therapeutic approach.

An improved understanding of specific early indicators of reading problems has been a major scientific breakthrough of the last decade. Individual study results (e.g., Badian, 1998; O’Connor & Jenkins, 1999; Storch & Whitehurst, 2002) as well as research syntheses (e.g., Hammill, 2004; National Early Literacy Panel, 2008) have provided convincing evidence regarding the importance of children’s early achievements in emergent literacy, including print knowledge and phonological awareness, to their later proficiency in reading specifically and academics more generally. Consequently, children who exhibit under-developed skills in emergent literacy development in the years just prior to receipt of formal reading instruction face increased risks for having problems with achieving skilled reading (Catts, Fey, Tomblin, & Zhang, 2002; O’Connor & Jenkins, 1999). By extension, these children are good candidates for early interventions focused on emergent literacy development (e.g., Byrne & Fielding-Barnsley, 1991; Justice & Ezell, 2002; Lonigan & Whitehurst, 1998; Wasik & Bond, 2001). Nonetheless, research aimed at identifying approaches for intervening in the area of emergent literacy has lagged behind developmental research on this topic, most notably as it concerns children who exhibit extreme vulnerabilities in emergent literacy development, such as children with language impairment (LI).

The present study contributes to a developing research literature concerned with identifying efficacious means for increasing the emergent literacy skills of young children with LI. Although intervention research focused on some aspects of emergent literacy is reasonably well-developed, particularly as concerns phonological awareness (e.g., Gillon, 2000; Justice, Kaderavek, Bowles, & Grimm, 2005; Segers & Verhoeven, 2004), there have been very few studies focused on other key areas of emergent literacy development, including print knowledge (but see Justice, Chow, Capellini, Flanigan, & Colton, 2003; Lovelace & Stewart, 2007; McNamara, Vervaeke, & Van Lankfeld, 2008). In this manuscript, we present findings concerning the feasibility, efficacy, and social validity of an early intervention approach designed to increase the print knowledge of young children with LI. This multi-dimensional construct describes children’s knowledge of the forms and functions of print (McGinty & Justice, 2009; Storch & Whitehurst, 2002). It includes both alphabet knowledge, which refers to an individual’s knowledge of the individual letters comprising the written alphabet, and print-concept knowledge, which refers to an individual’s knowledge of the specific rules that govern how print is organized in various texts. These and other indicators of print knowledge are among the strongest predictors of children’s later outcomes in word reading and reading comprehension (Badian, 1998; Catts et al., 2002; Hammill, 2004; National Early Literacy Panel, 2008).

Of relevance to the present study, children who exhibit LI as a primary or secondary disability in the years prior to beginning reading instruction exhibit significantly less knowledge about print compared to their typical peers (Boudreau & Hedberg, 1999; Cabell, Justice, Zucker, & McGinty, 2009; Justice, Bowles, & Skibbe, 2006). Recent reports show that the gap in print knowledge between typical preschoolers and those with LI is very large during the preschool years (e.g., d = −1.57 and −1.2 for alphabet knowledge and print-concept knowledge, respectively; see Cabell et al., 2009; Justice et al., 2006). These early gaps may directly contribute to the reportedly high rates of reading disability among children with LI in the later primary grades, as their reading growth does not sufficiently accelerate within the context of formal reading instruction to overcome these early disparities (Catts, Bridges, Little, & Tomblin, 2008; Skibbe, Grimm, Stanton-Chapman, Justice, Pence, & Bowles, 2008). Some estimates suggest that more than one-half (53%) of children with LI will exhibit reading disability in second grade (Catts et al., 2002). Longitudinal studies have suggested that certain factors elevate risks for primary-grade reading difficulties among children with LI; these include (a) presence of receptive language difficulties at school entry/kindergarten (Justice, Bowles, Pence Turnbull, & Skibbe, 2009), (b) persistence of language difficulties to second grade (Catts et al., 2002), and (c) co-occurrence of language difficulties and relatively low nonverbal IQ (between 70 and 85; see Catts et al., 2002). Identifying feasible, efficacious, and socially valid means for increasing print knowledge among children with LI in the preschool years, while simultaneously addressing core deficits in language ability, is a significant goal of emergent literacy research.

Studies of how to improve print knowledge among young children who exhibit risk (primarily attributable to being reared in poverty) have identified several promising approaches. These include literacy-enriched dramatic play (e.g., Neuman & Roskos, 1993; Vukelich, 1994), mediated writing (Aram & Biron, 2004), systematic curricula (DeBaryshe & Gorecki, 2007; Fischel et al., 2007), and shared storybook reading with a print-referencing style (Justice & Ezell, 2002; Justice, Kaderavek, Fan, Hunt, & Sofka, 2009). Shared storybook reading with a print-referencing style is perhaps the most strongly supported of these approaches, given that four separate experimental studies have demonstrated its causal impacts on young children’s print knowledge (Justice & Ezell, 2000, 2002; Justice et al., 2009; Lovelace & Stewart, 2007). This body of work shows that children’s exposure to a print-referencing style of shared book reading directly affects their growth of important emergent literacy skills, among them alphabet knowledge and print-concept knowledge. In turn, these short-term gains lead to longitudinal improvements in decoding, reading comprehension, and spelling through first grade (Piasta, Justice, Kaderavek, & McGinty, 2010). This approach to intervention, hereafter referred to as print-referencing intervention, is the focus of the present study.

Print-referencing intervention involves adult-child repeated reading of print-salient storybooks (i.e., storybooks with compelling print features, such as font changes and character speech bubbles) coupled with adult use of specific verbal and nonverbal references to print, such as pointing to print in the book and asking questions about print features (Justice & Ezell, 2004). These print references are used to systematically address specific print-related targets pertaining to general print concepts (e.g., directionality of print in books), letters (distinctive features and names of individual letters), and words (e.g., relations between letters and words) targeted horizontally within a reading session and cyclically over time (Justice et al., 2009). Experimental research suggests that the primary mechanism through which this approach exerts its effects on children’s development of print knowledge is by increasing the frequency with which children actively attend to print while decreasing children’s focus on illustrations (e.g., Evans, Williamson, & Pursoo, 2008; Justice, Pullen, & Pence, 2008). In turn, the amount of time children spend attending to print within storybooks has both immediate (Evans et al., 2008) and long term effects (Justice et al., 2008) on children’s print knowledge.

Theoretically, print-referencing intervention draws upon a conceptual framework commonly applied in emergent literacy research regarding the role of parents (and other adults) in socializing their children to the forms and functions of literacy; this socialization occurs within a range of literacy practices, including shared reading interactions and writing experiences, and is often referred to as social practice (e.g, Hammett Price, van Kleeck, & Huberty, 2009; Wells Rowe, 2008). Seminal research of Snow and Ninio (1986) situating literacy as a social practice (through which children internalize forms and functions of written language) described how parents socialized their children, even at very young ages, to learn the “contracts of literacy;” these include learning about how books are handled and the directionality of print, for instance. A fundamental perspective inherent to Snow and Ninio’s work is that parents’ socialization of children was largely implicit in nature: children were not explicitly taught about literacy but rather intuited much of their understandings on their own. In more recent years, and influenced largely by quantitative research paradigms, scholars have increasingly emphasized the importance of explicitness as a means for facilitating children’s literacy development, particularly children’s internalization of forms and functions of written language (Connor, Morrison, & Slominski, 2006). Explicit instruction is highly specific in its focus, such that a given activity is systematically tailored to arrive at a specific outcome (Connor et al., 2006). Print-referencing intervention therefore builds upon a theoretical framework that emphasizes literacy as social practice, in that children’s literacy skills are fostered within authentic and meaningful social interactions, but it also draws upon recent findings regarding explicitness as an important mechanism in literacy development.

Some evidence suggests that children with LI may benefit from exposure to print-referencing intervention, particularly research by Lovelace and Stewart (2007) which sought to determine the efficacy of this approach for children with LI. In their work, five children with LI received print-referencing intervention during 10-min reading sessions embedded into 30-min one-on-one language therapy sessions; sessions were conducted twice weekly by one of the study authors in a center-based early education program. As a function of the single-subject multiple-probe research design (in which children entered the intervention phase of the study following variable-length baseline conditions), children received the print-referencing intervention at various intensities, ranging from about 9 to 27 sessions. Each child showed observable improvements on probes of print-concept knowledge upon entry to the print-referencing intervention, consistent with a large effect size. As a result, the authors concluded that print-referencing intervention offers a means for “assisting young children with language impairment to acquire emerging literacy skills” (Lovelace & Stewart, 2007, p. 26). Although these are promising results regarding the efficacy of print-referencing intervention for children with LI, it is unclear whether the results are generalizable because of the limited number of cases analyzed (Horner, Carr, Halle, McGee, Odom, & Wolery, 2005) as well as the single context in which intervention occurred. At the same time, this study included only a single measure of print-concept knowledge. It’s unclear whether this intervention approach might impact other aspects of print knowledge (e.g., alphabet knowledge).

The present study builds upon this prior research base by examining the impact of print-referencing intervention as implemented by parents of children with LI within the home environment during a three-month shared reading program. The rationale for focusing on the potential effects of this intervention as implemented by parents within the home environment was based on three findings apparent from the extant literature. These concern the intervention’s feasibility (the extent to which an intervention can realistically be implemented and maintained), efficacy (the extent to which an intervention exerts causal impacts on targeted behaviors and skills), and social validity (the extent to which an intervention is viewed as acceptable and important in a given context, particularly as related to targeted outcomes; Foster & Mash, 1999).

First, regarding feasibility, print-referencing intervention appears amenable to parental implementation because it is confined to a single and naturalistic activity which is a regular occurrence in many children’s homes (Kuo, Franke, Regalado, & Halfon, 2004). In fact, the majority of American preschoolers are read to every day, according to parental report, although the percentage who experience daily reading ranges from about 40% to 74% as a function of family socioeconomic status (Kuo et al., 2004). A substantial number of studies have shown that many parents are able to implement book-reading programs in their homes to the benefit of their children (Arnold, Lonigan, Whitehurst, & Epstein, 1994; Crain-Thoreson & Dale, 1999; Dale, Crain-Thoreson, Notari-Syverson, & Cole, 1996; Lonigan & Whitehurst, 1998; Whitehurst et al., 1994). Nonetheless, it is necessary to explicitly examine feasibility in the present work given that the majority of prior studies on home reading programs have involved much shorter duration reading programs (≤ 6 weeks). In this study, a 12-week program was implemented based on the assumption that children with LI may require relatively intense intervention to experience meaningful levels of growth, based on prior research involving this population (e.g., Fey, Cleave, Long, & Hughes, 1993; Lovelace & Stewart, 2007). However, it is unclear whether a program of this duration is feasible for many parents. Prior research on the efficacy of home-reading programs has oftentimes involved highly-educated (middle-class) parents reading with their typically developing children (e.g., Whitehurst et al., 1988). When studies have involved more diverse representation of parents and children, such as parents from low-income backgrounds or children with disabilities, parents not only attrite but compliance becomes highly variable (Crain-Thoreson & Dale, 1999; Lonigan & Whitehurst, 1998; Whitehurst et al., 1994).

Second, with respect to efficacy, parental delivery of print-referencing intervention in the home environment with their typically developing children has demonstrated causal impacts on children’s print knowledge; importantly, the magnitude of these effects have been comparable to those found in researcher- and teacher-administered interventions (Justice & Ezell, 2000, 2002; Justice et al., 2009). This parallels earlier findings involving direct comparison of a parent-versus teacher-implemented book-reading program designed to facilitate the language skills of low-income preschoolers, which found the home-based program to have superior effects for some child outcomes (Lonigan & Whitehurst, 1998). Similarly, a direct comparison of a 4-month language therapy program for children with LI as delivered by parents compared to licensed speech-language pathologists found children’s language growth to be comparable (Fey et al., 1993). Such evidence suggests that it is both worthwhile and necessary to experimentally assess whether the positive effects of print-referencing intervention as occur when implemented by parents of typical children also occur for parents reading to their children with LI.

Third, with respect to social validity, we have seen from prior work that parents of both typically developing children (Justice & Ezell, 2000) and children with disabilities (Ezell, Justice, & Parsons, 2000) value their participation in print-referencing intervention programs. Social validity assessments implemented in one study involving four parents of children with disabilities who implemented print-referencing intervention at home for five weeks found that 100% of parents perceived it to be highly valuable and beneficial to their children (Ezell et al., 2000). Because they are important consumers of print-referencing intervention, parents’ subjective interpretations of the acceptability and importance of this intervention are included as a focus of this study.

In sum, this study was designed to address three questions: (1) To what extent is it feasible for parents of children with LI to complete a 12-week home-based book reading intervention? (2) To what extent do children with LI show increases in print knowledge as a result of participating in a 12-week home-based book reading intervention? (3) To what extent do parents and children exhibit satisfaction with completing a 12-week home-based intervention?

Method

Participants

Participants in this study were 62 primary caregivers (primarily mothers, although a father and custodial grandmother also participated) and their 4-year-old children with LI. All activities were approved by the Institutional Review Board of the host university. For the sake of simplicity, in the remainder of this report we refer to the primary caregivers as parents.

Eligibility requirements.

To participate in this study, children were required to meet a series of eligibility criteria designed to identify presence of LI. Specifically, each child was required to exhibit significantly depressed language skills relative to age-based normative references, pass a bilateral hearing screening at 25 dB across three frequencies (1,000; 2,000; 4,000), receive a standard score of 80 or higher on a measure of nonverbal cognition (i.e., matrices subtest of the Kaufman Brief Intelligence Test- 2; KBIT-2; Kaufman & Kaufman, 1990), and have an unremarkable sensory, motor, and neurological history per parental report. Depressed language skills were operationally defined for this study as receiving a score below the 10^th percentile on at least two subtests of the Test of Language Development-3: Primary (TOLD-P:3; Newcomer & Hammill, 1997) and a composite standard score less than or equal to 85 on either the Spoken Language or Syntax Quotient on the TOLD-P:3. Additionally, to participate in the larger study, the child’s primary parent (viz., the parent who would be implementing the reading program) was required to read at a fourth grade level or above as measured by the Wide Range Achievement Test (WRAT; Wilkinson, 1993). Although all parents met this study requirement, there was variability in parents’ reading abilities (see Table 1).

Table 1.

Caregiver and Child Characteristics (n = 62)

Variable	M	SD
Caregivers
Maternal age (in yrs)	34.1	6.9
Maternal education	5.1	1.2
Paternal education	4.8	1.5
Maternal reading	48.5	6.9
Children
Age (in months)	54.6	3.4
Receptive language	91.6	10.7
Expressive language	83.4	5.9
Print-concept knowledge	5.4	2.5
Alphabet knowledge	7.5	8.7

Note: Maternal and paternal education based on categorical scale to represent highest grade completed (1 = < 7^th grade; 2 = 7–8^th grade; 3 = some high school; 4 = high school diploma; 5 = some college; 6 = university degree; 7 = post-graduate training). Maternal reading = raw score on Wide Range Achievement Test (Wilkinson, 1993). Receptive language and expressive language = Listening Quotient and Speaking Quotient, respectively, of the TOLD-P:3; print-concepts = raw score of the PWPA; alphabet knowledge = Upper-Case Alphabet Recognition subtest of PALS-PreK.

Sample description.

The children (43 boys, 19 girls) ranged in age from 48 to 60 months (M = 55 months, SD = 3.4). The majority of children were Caucasian (n = 47; 76%), although other ethnicities/races were represented (7 African American, 4 Multi-Racial, 2 Hispanic, and 2 ‘Other’). Parents reported a median annual household income of $48,000 (SD = $34,000). As a separate index of socioeconomic status (SES), information about the mothers’ and fathers’ educational attainment was also collected. The highest level of educational attainment for the mothers was variable: five mothers (8% of sample) had not completed high school, 15 (24%) had high school diplomas, 15 (24%) had some college education, and 27 (44%) had four-year college and/or advanced degrees. As for fathers, eight (13% of sample) had not completed high school, 23 (37%) had high school diplomas, eight (13%) had some college education, and 23 (37%) had four-year college and/or advanced degrees. Based on these demographic data, the sample is best characterized as comprising both lower- to middle-SES families. Information regarding home-literacy practices of these families indicated that the majority of children (95%) were read to at least several times each week, if not daily (see Skibbe, Justice, Zucker, & McGinty, 2008).

Group assignment.

Following eligibility, dyads were randomly assigned to one of three intervention conditions that involved planned variations in the way parents read books with their children over a 12-week period: (1) print-referencing condition, in which parents integrated nine questions about print into each of 48 reading sessions (n = 21), (2) picture-focused condition, in which parents integrated nine questions about the illustrations and storyline into each reading session (n = 19), and (3) sound-focused condition, in which parents integrated nine questions about phonological concepts into each of 48 reading sessions (n = 22). The second and third conditions were designed to serve as alternative theoretical counterfactuals to the print-referencing condition. The picture-focused condition provides a direct test of whether print-referencing promotes children’s literacy development relative to a business-as-usual reading style (in which pictures and the storyline are the focus), and the sound-focused condition provides a direct test of whether print-referencing promotes children’s literacy development compared to an alternative literacy-focused reading style, albeit one in which phonological patterns are the foci.

General Procedures

Dyads entered into the study at any given point over a three-year period. Recruitment materials were made available over an approximately 180-mile radius of the university research site using multiple mechanisms (e.g., posting flyers in day care centers, sending letters to speech-language pathologists). The radius included all geographic typologies (rural, suburban, and urban) and spanned three different states. Interested parents were requested to contact the research site by telephone, at which point they would complete a brief screener to determine if their children met a general profile of LI (i.e., did not have a prior diagnosis of autism, hearing loss, or other congenital/chronic disabilities) and were of the appropriate age range for the study.

Following the initial telephone screening protocol, a 120-min home visit was conducted by two members of the research team, one of whom worked with the parent and the other of whom worked with the child. After discussing the nature of the study and informed consent, parents completed questionnaires about their child, their family, and their home literacy activities (see Skibbe et al., 2008 for more information). Each parent was also administered a measure of word recognition ability (i.e., WRAT; Wilkinson, 1993) and was required to achieve a score consistent with at least a fourth grade reading level.

Simultaneously, the child completed an individually administered set of assessments designed to document presence of LI (i.e., nonverbal test of cognition, language assessment). A measure of articulation/expressive phonology was also included for descriptive purposes (i.e., Goldman-Fristoe Test of Articulation; Goldman & Fristoe, 2000). Together, this protocol took approximately 30 to 40 minutes to administer. After determining eligibility, the child completed a second battery of approximately 15-min duration that included tasks designed to examine emergent literacy skills, to be described in greater detail below.

While children completed this second battery, parents received written instructions accompanied by verbal explanation about the book reading program they would implement within their homes for the forthcoming 12-week period. These instructions were identical for all parents, and included the following: (a) that parents would read a new storybook each week for 12 weeks in four separate one-on-one reading sessions with their child (at times selected by parents); (b) that parents should follow the schedule of titles as specified (Appendix A), with new titles introduced on Sunday of the week; (c) that all reading sessions should be audiotaped and sent to the research lab (every two weeks using stamped addressed mailers provided) accompanied by a written log documenting all completed readings; and (d) that parents should embed into their reading sessions nine questions affiliated with each book (discussed below). At the initial home visit, parents received all materials necessary for completing the program, including the first six weeks of books. (The second batch of six books was sent to parents by mail at the five-week mark.) The storybooks all featured interesting print characteristics (e.g., speech bubbles, large narrative print). Parents received a written schedule identifying the title of each week’s book along with the specific dates for which it was to be read (e.g., July 1-July 8); this schedule also doubled as a log, with space for parents to record the date and duration of each reading. As a gift for participating, parents received a check for $100 at the end of the study and were permitted to keep all study materials, including the set of 12 storybooks. What distinguished the reading program for the print-referencing and comparison reading conditions was exclusively the way in which parents were to read each book, as discussed next.

Print-referencing condition (treatment).

Parents in the print-referencing condition were asked to engage their children in explicit discussions about print within the storybooks during each reading session. They were asked to use nonverbal (e.g., pointing to print) and verbal strategies (e.g., commenting about print) to do so. Also, to facilitate these discussions, nine questions were pasted into the pages of each book that focused on three sets of print-related targets: (a) print concepts (e.g., Where should I start to read on this page?), (b) letters (Where is the first letter on this page?), and (c) words (Can you find the really long word on this page?). There were three questions per target within each book, all printed in 12-point font on small labels that were pasted directly into the book. This number of questions was found to be effective for increasing the print knowledge of children during an 8-week, 24-session book reading program conducted in Head Start settings (Justice & Ezell, 2000).

Comparison conditions.

The home-reading program completed by parents in the picture-focused and sound-focused reading conditions was identical in all ways to that of parents in the print-referencing condition, with one exception. Parents in the picture-focused reading condition embedded nine questions concerning characters and actions represented in the story (e.g., How does the farmer feel now? How is he feeling in this picture?) as well as at least three prediction questions per book (e.g., What do you think is going to happen next?). Parents in the sound-focused condition embedded nine questions about phonological concepts into each book, three focused on rhyme patterns (e.g., Did you hear a word that rhymes with cat?), three on beginning sounds (e.g., What sound does house start with?), and three on syllable structure (e.g., How many parts are in the word monster?).

Fidelity of implementation.

Parents’ fidelity of implementation was supported and monitored using several strategies. First, parents were contacted by telephone each week of the 12-week reading program by research staff. Staff had brief, informal conversations with parents with two aims: (a) to remind parents to continue implementing the program as scheduled, and (b) to troubleshoot any problems that parents may be experiencing (e.g., tape-recorder malfunctions, vacation schedules). The rate of ongoing personal contact was quite high, with all parents contacted at least 11 of 12 possible weeks.

Second, parents were provided a log on which to record all readings taking place; these logs were submitted every two weeks to project staff and were reviewed for completeness.

Finally, parents were asked to record their 48 home-based reading sessions using cassette tapes and a tape recorder provided. One tape was provided for each two-week period, for a total of six possible tape submissions forwarded to project staff by parents at the end of each two-week segment of the program. One-half of the reading sessions on each tape received were randomly selected and listened to by research personnel in their entirety to document that (a) each book was read as scheduled and (b) the nine scripted questions were implemented within each book by the parent. In total, 593 audiotaped reading sessions submitted by parents were analyzed. In 97% of sessions (577 of 593), the scheduled book was read in its entirety. Regarding implementation of the nine questions, fidelity was 100% in 88% of sessions (522 of 593); 89% in 9% of sessions (55 of 593, which corresponded to missing one of the nine scripted questions); 78% in 2% of sessions (11 of 593); and < 78% in 1% of sessions (5 of 593). As these data show, the parents overall exhibited high fidelity to both the reading schedule and the embedding of questions into reading sessions. In instances in which parents’ implementation did not achieve the desired level of fidelity or implementation did not adhere to study conditions, the importance of implementing the program as requested was emphasized in the next phone call.

Measures

Feasibility measure.

Feasibility of implementation was assessed exclusively by determining whether or not a dyad completed the program; we viewed this as the most definitive way of establishing whether parents could feasibly maintain the program to completion. As noted previously, as part of the study methods parents were contacted by telephone each week of the study. During these calls, some parents indicated to study staff that they would no longer be implementing the home reading program with their children. In such instances, research staff documented the reasons for attrition. These parents should be distinguished from parents who continued through the end of the program but did not implement all reading sessions.

Efficacy measures.

Children were administered a set of direct assessments at pretest and posttest examining two dimensions of print knowledge: print-concept knowledge and alphabet knowledge. These measures were administered to children individually in their homes by research assistants who had completed training protocols for each.

Children’s print-concept knowledge and alphabet knowledge were assessed, respectively, with the Preschool Word and Print Awareness (PWPA; Justice et al., 2006) and the Phonological Awareness Literacy Screening for PreK (PALS-PreK) Upper-case Alphabet Recognition subtest (Invernizzi, Sullivan, & Meier, 2001). The PWPA assesses children’s knowledge of 14 print specific concepts in the context of a shared book reading using a commercial storybook; while reading the book with the child, the examiner embeds questions about specific print concepts. For instance, the first task involves the examiner handing the storybook to the child (spine facing the child) and requesting that the child “Show me the front of the book.” This is followed by additional tasks (e.g., “Show me where I begin to read;” “Show me just one word on this page;” Show me the first line on this page.”), all of which are situated within an authentic reading of the text. Correct responses receive either one or two points, with partial credit allowable on the two-point questions, resulting in a total possible raw score of 17 points. The PWPA demonstrates adequate construct validity, inter-rater reliability, and individual item functioning (see Justice et al., 2006). The Upper-case Alphabet Recognition subtest of the PALS-PreK requires children to name the 26 individual upper-case letters of the alphabet. One point is awarded for every letter correctly identified, for a total of 26 points. This measure also has desirable psychometric properties (Invernizzi et al., 2001).

Social validity.

Parents’ perceptions regarding various elements of the home-based intervention program were evaluated using a 6-item questionnaire adapted from similar prior studies (e.g., Ezell et al., 2000). The six items appear in Appendix B. These items examined parents’ and children’s enjoyment of the reading sessions and the books used, as well as parental perceptions regarding how useful they believed the sessions to be for their children. Parents responded to each item using a 5-point Likert-type scale, with 1 representing not at all and 5 representing very much. Parents completed the questionnaire during their children’s posttest assessment. Parents were asked to complete the questionnaire anonymously, to answer each question as accurately and honestly as possible, and then to place it in a sealed envelope.

Results

Feasibility

The first research question sought to determine the extent to which parents could feasibly implement a 12-week intensive home-based book reading intervention involving implementation of 48 one-on-one reading sessions with their children with LI. We addressed this question descriptively by examining attrition rates of the book-reading intervention. A total of 62 parents were randomly assigned to the intervention conditions and began the home-based reading programs; subsequent to this, 14 parents (23% of the sample) attrited from the study and did not complete the program. This attrition rate is less than the 30% benchmark desirable for group-design experimental research (Gersten et al., 2005), but it also shows that the intervention was not feasible for about one-fourth of the sample. The reasons parents gave for non-completion included illness-related issues (n = 2); time constraints, as attributable to such factors as the parent going back school, taking a second job, or giving birth (n = 6); child custody issues (n = 1); and parent-reported difficulty with reading (n = 2). In three instances, the parent did not provide a reason.

We questioned whether attrition rates differed significantly across conditions. Overall, 5 of 21 dyads (24%) attrited from the print-referencing condition, 6 of 19 dyads (32%) from the picture-focused condition, and 3 of 22 dyads (14%) from the sound-focused condition. Although the attrition rates across the three conditions ranged from 14% to 32%, the probability of attrition was not significant different among the three groups, χ²(1, N = 62) = 1.905, p = .386. Looking specifically at pair-wise comparisons, parents in the print-referencing condition were no more likely to drop out than those in the picture-focused condition, χ²(1, N = 40) = .302, p = .58, or the sound-focused condition, χ²(1, N = 43) = .734, p = .39.

For exploratory purposes, we asked whether there were certain dyad characteristics that differentiated completers (n = 48) from non-completers (n = 14) (see Table 2). We focused on caregiver age, maternal and paternal educational attainment, maternal reading ability, child age, child language skills (based on the Spoken Language Quotient of the TOLD-P:3), and child literacy skills (based on the print-concept knowledge and alphabet knowledge measures). Results of analyses of variance (ANOVA), in which we used a standard alpha level of .05 given the exploratory purposes, showed statistically significant differences between completers and non-completers on several variables: maternal age was lower for non-completers than completers, F (1,60) = 5.85, p = .019 (d = 0.73) as was maternal and paternal educational attainment, respectively: F (1,61) = 8.48, p = .005 (d = 0.88), and F (1,61) = 3.96, p = .05 (d = 0.62). To explore more closely the potential relation between parental educational attainment and attrition, we examined attrition rates as a function of whether a child’s mother or father had completed high school. The probability of attrition was significantly higher if a child’s mother, χ²(1, N = 62) = 10.257, p = .001, or father, χ²(1, N = 62) = 8.733, p = .004, had not completed high school. Comparisons made for maternal reading ability, child age, and child language and literacy skills did not show any significant differences between completers and non-completers

Table 2.

Caregiver and Child Characteristics: Completers and Non-Completers

Variable	Completers (AT Sample) (n = 48)		Non-Completers (n = 14)
	M	SD	M	SD
Caregivers
Maternal age (in yrs)	35.2	7.1	30.3	4.7
Maternal education	5.4	1.1	4.4	1.2
Paternal education	5.0	1.4	4.1	1.5
Maternal reading	49.1	6.9	46.5	6.5
Children
Age (in months)	54.8	3.4	53.8	3.7
Receptive language	92.0	10.1	90.1	12.9
Expressive language	83.9	6.3	81.8	4.2
Print-concept knowledge	5.6	2.6	4.6	2.2
Alphabet knowledge	7.0	7.9	9.5	11.2

Note: Maternal and paternal education based on categorical scale to represent highest grade completed (1 = < 7^th grade; 2 = 7–8^th grade; 3 = some high school; 4 = high school diploma; 5 = some college; 6 = university degree; 7 = post-graduate training). Maternal reading = raw score on Wide Range Achievement Test (Wilkinson, 1993). Receptive language and expressive language = Listening Quotient and Speaking Quotient, respectively, of the TOLD-P:3; print-concepts = raw score of the PWPA; alphabet knowledge = Upper-Case Alphabet Recognition subtest of PALS-PreK.

Efficacy

The second question addressed in this study aimed to determine the extent to which children showed improvements in print knowledge attributable to their participation in print-referencing intervention. To address this question, data analyses only included children who had completed the intervention. This type of analyses, referred to as as-treated analysis (AT) because it involves only children who completed the intervention, should be distinguished from intent-to-treat analysis (ITT), which involves children as randomized (all those who we intended to treat). Table 2 provides a comparison of the AT sample (i.e., intervention completers) in relation to the ITT sample (intervention non-completers). These terms come from the medical literature to represent an important distinction in the analysis of clinical trials featuring randomization (upon which causal interpretations rely) after which subjects are lost due to mortality or infidelity (Frangakis & Rubin, 1999). Readers should recognize that AT analyses may result in biased estimates of intervention efficacy, because non-completers tend to differ in important (but oftentimes unknown) ways from completers.

Descriptive data detailing children’s gains over the 12-week intervention period on the two print knowledge measures appear in Table 3. Analyses of variance were used to assess between-group differences on gain scores calculated for each of the two dependent measures; results showed a significant between-group difference for print-concept knowledge, F (2,47) = 3.457, p < .05, but not for alphabet knowledge, F (2,47) = .13, p > .05. Post-hoc tests (Tukey HSD) to further examine the significant main effect showed that children in the print-referencing condition made significantly greater gains (M = 4.7, SD = 3.1) than those in the picture-focused condition (M = 1.6, SD = 3.4) on the print-concept knowledge measure (d = 0.92), consistent with a large effect size. The print-concept knowledge gains for those in the print-referencing condition (M = 4.7, SD = 3.1) were not significantly greater than those in the sound-focused condition (M = 2.8, SD = 3.1); however, the effect-size estimate (d = 0.58) favored those in the print-referencing condition and there was a trend towards a significant difference (p = .09). In general, on the PWPA, being in the print-referencing condition constituted an advantage of nearly one standard deviation unit relative to the picture-focused reading condition and about one-half of a standard deviation unit relative to those in the sound-focused condition.

Table 3.

Scores on Language and Literacy Measures by Condition for AT Sample

Variable n	Print-Referencing 17		Picture-Focused 12		Sound-Focused 19
	M	SD	M	SD	M	SD
Pre-test scores
Receptive language	90.5	12.8	97.0	11.1	93.1	9.2
Expressive language	81.4	5.1	81.3	11.0	85.8	6.5
Print-concept knowledge	5.9	2.2	6.3	2.6	5.3	2.7
Alphabet knowledge	7.1	9.4	11.6	9.3	8.5	9.1
Posttest scores
Print-concept knowledge	10.5	3.3	7.9	2.3	8.3	2.8
Alphabet knowledge	10.6	9.3	14.3	10.4	11.0	9.7

Note: Receptive language and expressive language = Listening Quotient and Speaking Quotient, respectively, of the TOLD-P:3; print-concept knowledge = raw score of the PWPA; alphabet knowledge = Upper-Case Alphabet Recognition subtest of PALS-PreK

The lack of a significant difference among groups on the alphabet-knowledge measure was unexpected, particularly given that parents in the print-focused reading sessions explicitly targeted letters in the intervention. In fact, children in all three conditions learned an average of three letters during the intervention period. We questioned whether parents in the picture-focused condition did, in fact, discuss print generally or letters more specifically when reading with their children, a possibility given that the books provided all contained interesting print features. Of the 24 audio-taped reading sessions submitted by the 12 parents in the picture-focused condition, two per parent were randomly selected and coded for parental references to print using a comprehensive extant coding system designed for this purpose (see Zucker, Justice, & Piasta, 2009). This coding system identifies the raw frequency by which a parent explicitly references any aspect of print within a text. Coding was completed by two individuals, blind to the goals of this study, who had previously been trained to criterion on this instrument (see Zucker et al., 2009). Of the sessions coded, 71% (n = 16) included no parental print references, four contained one reference, one contained two references, and one contained six references. In these 22 of 24 sessions, the frequency of print references falls short of what occurred in the print-focused sessions and what has been shown to be efficacious in the extant literature. The remaining two sessions contained 14 and 16 print references, both by the same parent, and 90% (28/30) were focused on letters within the books. Removal of this child’s score did not change the main effects reported earlier.

Social Validity

As the only study of which we are aware that has involved implementation of an extensive home book-reading program for children with LI, an important goal of this study was to characterize parental perceptions of the program’s acceptability and importance. Anonymous questionnaires were completed by 44 of the 48 parents (16 in the print-referencing condition, 12 in the picture-focused condition, and 16 in the sound-focused condition). Table 4 provides parental responses to the six questionnaire items, four of which concerned the experiences of the parents and two of which concerned the children’s experiences. These descriptive data suggest that parents in both conditions viewed the 12-week book reading program favorably, with mean scores (on a 5-point scale) exceeding 4 for all questionnaire items across both groups. Note also that ratings were slightly higher on five items for participants in the print-referencing condition.

Table 4.

Parental Responses to Social Validity Questionnaire Items by Condition

	Reading Condition
Questionnaire Item	Print-Referencing M (SD)	Picture-Focused M (SD)	Sound-Focused M (SD)
Caregiver enjoy reading sessions	4.8 (0.4)	4.7 (0.5)	4.6 (0.5)
Caregiver perceive as helpful to child	4.3 (0.6)	4.0 (0.9)	4.4 (0.7)
Caregiver continue using techniques	4.9 (0.3)	4.7 (0.7)	4.8 (0.4)
Caregiver do program again	5.0 (0)	4.7 (0.5)	4.9 (0.3)
Child enjoy reading sessions	4.9 (0.3)	4.3 (0.7)	4.4 (0.6)
Child enjoy books	4.8 (0.4)	4.3 (0.6)	4.6 (0.5)

Parents rated their perceptions on a five-point Likert-type scale, with 1 representing not at all and 5 representing very much.

To compare parent ratings across the groups for the six questions, a series of Mann-Whitney U tests were conducted with a Bonferonni correction (p < .008) given the multiple comparisons. For these tests, the two comparison groups (picture-focused, sound-focused) were collapsed to form a single group for the purpose of comparing parent ratings in the print-referencing condition against those collectively representing the contrast groups. As an estimate of the size of the effect, we report difference in mean ranks between the groups (Green & Salkind, 2008). Results showed two significant differences between groups, both of which concerned caregivers’ perceptions of children’s experiences. Specifically, parental ratings regarding how much children enjoyed the reading sessions were significantly higher for those in the print-referencing condition compared to those in the comparison conditions, z = −2.685, p < .008, as were ratings regarding how much children enjoyed the books used in the reading sessions, z = −2.677, p < .008. Parents in the print-referencing condition had mean ranks of 28.38 and 28.47, respectively, whereas parents in the comparison conditions had mean ranks of 19.14 and 19.09. There were no significant differences between parents’ ratings for the other four questionnaire items.

Discussion

The present study makes a direct contribution to the emerging literature on efficacious approaches to literacy intervention for preschool children with LI, and describes the feasibility, efficacy, and social validity of print-referencing intervention as implemented by parents of children with LI in the home environment. The particular intervention approach described here, in which print-focused interactions are embedded in adult-child shared reading, draws upon a conceptual framework that emphasizes literacy development as occurring largely through social practice (e.g, Hammett Price et al., 2009). This is coupled with increased awareness of the importance of explicitness within these interactions, as compared to implicitness, as a way to support children’s internalization of knowledge about print. This coupling of social practice routines with explicit literacy instruction designed to encourage literacy development has found support in prior research for children who are typically developing as well as those with LI (Justice & Ezell, 2000; Lovelace & Stewart, 2007). As would be expected based on these extant findings, but with several key qualifications, results of this work showed that (a) print-referencing intervention could be feasibly implemented by many (but not all) parents of children with LI in their homes, (b) children with LI who were exposed to the intervention experienced accelerated growth in one (but not both) of the outcomes studied as compared to typical picture-focused reading, and (c) parents perceived the intervention favorably, particularly with respect to their perceptions of children’s experiences. We discuss each of these findings in turn.

Feasibility of Parental Implementation

Prior studies have experimentally assessed the effects of parent-implemented home-reading programs upon young children’s language and literacy skills; one of the earliest and more influential studies of this type was reported in 1988 by Whitehurst and colleagues, then followed by a number of replications and extensions (e.g., Arnold et al., 1994; Crain-Thoreson & Dale, 1999; Dale et al., 1996; Lonigan & Whitehurst, 1998; Whitehurst et al., 1994). Many, but not all, of these studies showed that modifications in the way in which young children experienced shared reading in the home environment could afford positive benefits to children’s development, primarily in the area of vocabulary. Recognizing that such effects may not be externally valid to a range of diverse circumstances, some researchers have sought to determine whether such home-based reading programs are feasibly implemented by parents from low-income homes (Lonigan & Whitehurst, 1998; Whitehurst et al., 1994) and by parents reading with children who have disabilities (Crain-Thoreson & Dale, 1999; Dale et al., 1996). Although none of these studies studied feasibility, per se, findings have suggested that implementation of home-based reading programs are feasible for a majority of parents.

In the present study, we explicitly examined the issue of feasibility by determining how many parents could complete an extensive home reading program, even in the context of high levels of support (e.g., being provided all materials, being contacted on a weekly basis). Findings showed that completion of an intensive home-based reading program was not feasible for about one-fourth of the parents of children with LI, a finding that converges with some prior accounts. Crain-Thoreson and Dale (1999), for instance, studied the efficacy of an 8-week home-based reading program for children with disabilities; 14% of dyads attrited from the program, with time constraints and illness as the primary reasons reported by parents. Both Whitehurst et al. (1994) and Lonigan and Whitehurst (1998), in separate studies of the effects of six-week home-based reading programs involving low-income parents, found that compliance to the reading schedule varied widely, with Lonigan and Whitehurst reporting that only 60% of parents returned reading logs designed to assess fidelity of implementation. Given that the current reading program was twice as long as those described by these other research teams, it is not necessarily surprising that about one in four parents who started the program could not complete it.

Reported reasons for non-completion mirrored those available in the literature (family illness and time constraints; Crain-Thoreson & Dale, 1999), and was also significantly associated with two characteristics of children’s parents, namely mothers’ age and educational attainment of both parents (which were correlated among mothers in this sample, r = .33, p < .01). The mechanisms through which these parental characteristics exert their effects on completion of a home-based reading program can only be speculated. However, given the positive relations between maternal age and educational level in this sample, one possibility is that mothers who are younger and who are less educated are more likely to be furthering their education (e.g., pursuing a high-school equivalency diploma); in turn, this may create significant time constraints that lead them to attrite.

Alternatively, another possibility is that our findings may reflect the multiple risk factors associated with being a young mother and the conflation of maternal age and SES (Mayberry, Horowitz, & Declercq, 2007; Pogarsky, Thornberry, & Lizotte, 2006). A recent meta-analysis on the effectiveness of home-based interventions designed to improve parenting within the homes of young children showed that both maternal age and SES were important moderators of intervention outcomes (Bakermans-Kranenburg, van IJzendoorn, & Bradley, 2005). In fact, study authors reported that middle-SES families profit twice as much as low-SES families from home-based interventions, which they refer to as a Matthew Effect. In the present study, the Matthew Effect appeared to manifest itself in a different way, such that middle-SES dyads appeared more likely to complete the intervention compared to lower-SES dyads. With this in mind, an important outcome of the present study is that it identifies a clear need for future research that assesses how specific family characteristics may affect the feasibility of home-based interventions, particularly for parents of children with LI.

Efficacy of Print-Referencing Intervention for Children with LI

For those families who completed the study, the print-referencing intervention program was efficacious in boosting the print-concept knowledge of children with LI as compared to children who received picture-focused reading. In this comparison, effects were large in size and consistent with prior research showing positive impacts on print-concept knowledge for (a) children from low-income homes receiving print-referencing intervention in small-group sessions held at their preschools (Justice & Ezell, 2002), and (b) children with LI receiving print-referencing intervention in one-on-one therapy sessions (Lovelace & Stewart 2007). The mechanism underlying these effects relates, at least in part, to increases in children’s visual attention to and verbal discussions about print when reading with adults who reference print often; in turn, children have increased opportunities to internalize knowledge about the forms and features of print (Ezell & Justice, 2000; Justice et al., 2008).

Interestingly, children who participated in print-focused reading sessions did not have significantly larger gains in print-concept knowledge than those in the sound-focused condition. Although there was a clear trend (and moderately-sized effect) towards meaningful differences in gains between the two groups, to favor the print-referencing condition, we suspect that the lack of a significant difference between the groups stems from the fact that parents in the sound-focused condition used print-related cues to support their children’s performance on the phonological-concept tasks. We base this speculation on an intensive study of five parents repeatedly reading a single book within the sound-focused condition (Skibbe, Behnke, & Justice, 2004), in which parents were observed to use a number of print-related cues to support their children’s performance on the sound tasks (e.g., “Look at this letter, what sound does it make?”). We have also reported that parents implementing print-focused reading sessions often make reference to phonological concepts as well (Justice, Weber, Ezell, & Bakeman, 2002), suggesting that it may be difficult to truly isolate print- and sound-foci in early literacy interventions implemented by non-researchers.

While we can contend that print-referencing by parents had positive impacts on print-concept knowledge, relative to picture-focused reading, it is of note that children in this study who received print-referencing intervention did not experience any appreciable boost to their alphabet knowledge. This null finding contrasts with previous work, which demonstrated significant increases in alphabet knowledge for children from low-income homes who received print-referencing intervention as part of their preschool programs (Justice et al., 2009; Justice & Ezell, 2002). Nonetheless, it is also the case that no significant increase in alphabet knowledge was found when parents implemented a print-referencing intervention at home with their typically developing children (Justice & Ezell, 2000). Children in that study learned an average of one additional letter over a 4-week intervention, a rate of growth that resembles that of the present work, in which children in all three groups learned an average of about three additional letters over a 12-week intervention. The limited effects of print-referencing intervention on children’s alphabet knowledge as reported here and in Justice and Ezell (2002), both of which featured parent implementation of the intervention, suggests that parents may have special difficulty in this element of the intervention. It may be that improving children’s alphabet knowledge requires more intensive instruction and/or unique instructional approaches of which parents are not particularly skilled. For instance, as part of this study, parents would embed questions about specific letters into their reading sessions (e.g., “Do you know this letter?”); in instances when children could not accurately perform, it may be that parents did not know how to effectively support children’s performance to move them towards independence (e.g., by providing models and additional practice opportunities). That children showed so very little growth in this area suggests that this domain of development could be targeted more effectively.

Social Validity of the Book-Reading Program

The parents who completed this 12-week book-reading program perceived the intervention very favorably, particularly with respect to their perceptions of children’s experiences. This finding is a significant one, as the social validity of an intervention concerns the meaningfulness or acceptability of its processes and targets, and appears particularly relevant when considering whether an intervention is likely to be accepted by various consumers (Foster & Mash, 1999). Assessments of social validity, which often includes subjective evaluations of the type used here, can serve as outcome measures within clinical-outcomes research to supplement outcome measures that assess changes in directly treated skills and abilities (Foster & Mash, 1999). Given the duration of the intervention tested in this study, the finding that parents provided high ratings to the intervention is a promising finding concerning the social acceptability of the intervention’s goals and procedures by key consumers. Of additional note is that all parents who implemented the print-referencing intervention indicated that they would do this program again.

There were several appreciable differences between the three groups that warrant comment, particularly with respect to parents’ perceptions of their children’s experiences. Parents in the print-referencing condition provided significant higher ratings with respect to their children’s enjoyment of the reading sessions and of the storybooks as compared to parents in the comparison condition. This is a potentially important finding given reports in the literature that children’s enjoyment of reading experiences is an important mechanism for facilitating and maintaining reading growth over time (Frijters, Barron, & Brunello, 2000), and that children with LI may be more liable to not enjoy reading experiences compared to other children (Kaderavek & Sulzby, 1998). This finding is somewhat difficult to explain, however, given that children in both conditions read the same storybooks along the same schedule, which we would have thought would have resulted in similarly enjoyable circumstances. Moreover, parents in the comparison conditions did not know that they were implementing questions in their reading sessions that differed from other parents in the study, negating the likelihood of a Hawthorne effect. That children in the print-referencing condition did seem to enjoy their sessions and storybooks more so than other children, at least according to their parents, suggests that parental references to print may have changed the nature of the reading experience to make it more interesting (and thus, enjoyable) to children. Parents reading to their children seldom talk about print but often talk about the illustrations (Hammett Price et al., 2009). Similarly, parent rarely point out interesting print features, such as speech bubbles or environment print in the illustrations. It may be that children found the reading interactions and the books themselves more enjoyable as their parents broadened the experience to include discussion about print.

Limitations and Future Research Directions

Several salient limitations warrant note. First, data on 23% of children who were originally randomized into study conditions were unavailable at the close of the study. Although this attrition rate is not uncommon among book-reading research studies (e.g., Lonigan & Whitehurst, 1998), it is unclear whether the non-completers differ in important but unknown ways from the completers. If they did, it is possible that impact estimates are biased with respect to child effects. Consequently, results should be interpreted cautiously. Second, the resulting sample of dyads was relatively homogenous in several key ways. The sample included only English-speaking families, comprised relatively older (non-adolescent) parents, and included only children with language as a primary disability. It is unclear whether results can readily generalize to non-English-speaking parents, adolescent parents, and children with a broader range of developmental disabilities. Despite these limitations, the findings of this work provide an important foundation for clinical-outcomes research concerning the utility of home-based interventions; relatively few studies have rigorously studied the feasibility, efficacy, and social validity of interventions conducted with the homes of children with LI (but see Fey et al., 1993).

The results of this study suggest several potentially fruitful lines of research, particularly concerning matters of feasibility, efficacy, and social validity. First, concerning feasibility, it is apparent that some parents cannot complete extensive interventions as the kind studied here. This is a common issue in any of the literatures involving implementation of home-based education and care programs (e.g., caring for elders in the home, Montgomery, 1996), yet it is one that is too often neglected in clinical-outcomes research. The issue of intervention feasibility, particularly as concerns parent-implemented interventions for children with communication disabilities, warrants the field’s attention. Basic research is needed to identify family- and child-level factors that enhance or detract from feasibility, and applied research is needed to show how we might individualize interventions to make them feasible regardless of detractors. Second, regarding efficacy, study results suggest the importance of identifying ways to effectively improve alphabet knowledge in children with LI. Given the relevance of alphabet knowledge to early reading development, it is a concern that limited gains were apparent in a fairly intensive and targeted intervention as that implemented here. Finally, regarding social validity, a compelling question that emerged from this study is whether increasing the print focus of parent-child shared reading interactions increases children’s enjoyment of these sessions. In this study, children’s enjoyment was only estimated based on parent report; future studies that examine children’s enjoyment more directly and with multiple measures may help to identify specific mechanisms through which book-reading interventions exert their effects.

Appendix A. Titles Used in Home Reading Program by Week

Week 1: There’s a Monster in my House (Jenny & Hawthorne, 2003)

Week 2: Click, Clack Moo Cows that Type (Cronin, 2000)

Week 3: Puddles (London, 1997)

Week 4: Froggy Gets Dressed (London, 1992)

Week 5: The Awful Aardvarks Shop for School (Lindbergh, 2000)

Week 6: Growing Vegetable Soup (Ehlert, 1987)

Week 7: There’s a Dragon at my School (Tyler & Hawthorne, 1996)

Week 8: The Gigantic Turnip (Tolstoy & Sharkey, 1998)

Week 9: The Awful Aardvarks Go to School (Lindbergh, 1997)

Week 10: Chicka Chicka Boom Boom (Martin & Achambault, 1989)

Week 11: Silver Seeds (Paolilli & Brewer, 2001)

Week 12: Where’s Tim’s Ted? (Whybrow, 2000)

Appendix B. Items on Social Validity Questionnaire

[All items responded to on a five-point Likert-type scale (1 = not at all, 5 = very much)]

1. How much did you enjoy the reading sessions?

2. Overall, how much did the reading sessions help your child’s development?

3. How likely are you to keep using the techniques you used in your reading sessions now that the program is over (e.g., asking questions about certain things in the storybooks)?

4. How likely would you be to do a program like this again?

5. How much did your child enjoy the reading sessions?

6. Overall, how much did your child enjoy the books used in the reading sessions?