Table 1.
Summary of reviewed studies – phonological and/or semantic vocabulary intervention approaches.
| Authors, year, country | Design | Participants | Intervention | Dosage | Delivery | Outcome measure | Results | Follow-up | JBI quality rating* |
|---|---|---|---|---|---|---|---|---|---|
| Wing (1990), US | Non-randomized matched group comparison: 5 children per group | 8 males & 2 females with existing diagnosis of LI (age 5; 11–7; 1) | Phonological versus semantic approach | 30 × 25 min sessions over 2.5 months per group Total: 750 min/12.5 h Number of target words unclear |
Provider: School SLT Mode: Face-to-face group sessions in English Location: Room in specialist school | Within group, pre-post comparison using the standardized Test of Word Finding (German, 1986), a picture-naming test of expressive vocabulary | •Significant gain with phonological therapy (p < 0.05, d = 0.7, moderate effect) •Gain with semantic therapy was not significant | Not measured | Low quality |
| Wright (1993), UK | Matched no-treatment control group: 2 males & 2 females with SLI (aged 7; 9–8; 5) | 2 males & 2 females with existing diagnosis of SLI (age 7; 6–8; 8) | Combined phonological & semantic approach | 18 × 20 min sessions over 4 weeks Total: 360 min/6 h90 target words per child, each presented once | Provider: School SLT Mode: Face-to-face group sessions in English Location: Room in specialist school | Within group, pre-post comparison using a researcher-created picture-naming test of target words to assess expressive vocabulary | •Significant gain for target words (p < 0.01) & untargeted control words (p < 0.05) •No significant change for control group on any measure Effect sizes not reported |
Loss in gains at 1-month follow up | Medium quality |
| Parsons et al. (2005), UK | Pre-post comparison | 2 males with existing diagnosis of SLI (age 8; 10–9; 5) | Combined phonological & semantic approach | 18 × 25–35 min sessions. 2–3 sessions a week over 8 weeks Total: 450-630 min/7.5–10.5 h18 target words, single presentation in therapy with home-school reinforcement | Provider: Healthcare SLT with carer follow-up at home & teaching staff follow-up in class Mode: Face-to-face individual sessions in English Location: Room in mainstream school | 1. Individual pre-post comparison using a researcher-created test which matched targeted words with pictures/synonyms to assess receptive vocabulary 2. Individual pre-post comparison using standardized vocabulary measures: British Picture Vocabulary Scale (Dunn et al., 1982) to assess receptive vocabulary & Test of Word Finding (German, 1989) to assess expressive vocabulary |
1. Target word tests •Child A. Significantly greater gain for target words than control words (p < 0.01) •Child B. Significantly greater gain for target words than control words (p < 0.001) Effect sizes not reported 2. Standardized tests. No change for Child A or B |
Not measured | Medium quality |
| Zens et al. (2009), New Zealand | Randomized alternating treatment crossover design, no washout time in-between | 19 children with existing diagnosis of SLI (age 6; 2–8; 3, gender unknown) | Phonological/semantic/combined approach + Ongoing specialist support for 10 children (specifics unclear) | 12 h of one intervention over 6 weeks (2 × 1 h weekly) Followed by 12 h alternate intervention over 6 weeks (2 × 1 h weekly) Total: 720 min/12 h 27 target words, multiple presentations |
Provider: University-affiliated SLT Mode: Face-to-face group sessions in English Location: Room in mainstream school | 1. Within group, pre-post-test comparison using the standardized Test of Language Development 3rd Ed (Newcomer and Hammil, 1997) & a researcher-created categories test. Raw scores were combined to provide an expressive vocabulary score 2. Within group, pre-post-test comparison using the non-standardized Phonological Awareness Probes (Stahl and Murray, 1994): phoneme blending, isolation, segmentation & deletion |
1. Expressive vocabulary tests •Significant gain with phonological therapy (p = 0.001, f = 0.65, large effect) •Significant gain with phonological + semantic therapy (p = 0.001, f = 0.65, large effect) •Significant gains with semantic therapy (p = 0.004, f = 0.62, large effect) •Significant gain with semantic + phonological therapy (p = 0.004, f = 0.62, large effect) 2. Phonological awareness tests •Significant gain with phonological therapy (p < 0.001, f = 1.06, large effect) •Significant gain with phonological + semantic therapy (p < 0.001, f = 1.06, large effect) |
Not measured | Medium quality |
| •Significant gain with semantic + phonological therapy (p < 0.001, f = 1, large effect) •Gain with semantic therapy was not significant | |||||||||
| Motsch and Marks (2015), Germany | Randomized control trial. Control: 55 males & 24 females with SLI (mean age 9;6, SD 0.27) | 53 males & 25 females with existing diagnosis of SLI (mean age 9;6, SD 0.16) German-speaking. 38 children received group therapy (2 children per group). 40 received individual therapy |
Combined phonological & semantic approach + Variety of ongoing individual & group SLT/teacher language support (specifics unclear, however statistical significance of intervention gains maintained when this additional-support cohort removed) | 20 sessions once per week over 5 months. 45 min group sessions & 30 min individual sessions Total: Individual therapy – 600 min/10 h Group therapy – 900 min/15 h Number of target words unclear |
Provider: SLTs with home-school follow-up Mode: Face-to-face individual versus group sessions in German Location: Room in special schools | Within and between group pre-test to 4-month follow-up comparison using a range of standardized language tests in German (post-test scores not reported): 1. WWT 6–10 (Glück, 2011). A picture- naming test of expressive vocabulary 2. P-ITPA - Vocabulary subtest (Esser et al., 2010). A sentence-completion test to assess expressive vocabulary 3. P-ITPA – Analogies subtest (Esser et al., 2010). An analogy-generation test to assess expressive vocabulary 4. SET 5–10 (Petermann, 2010). A sentence comprehension to assess receptive syntax |
Within group 1. Picture naming test of expressive vocabulary •Significant gain with group therapy (p < 0.001, d = 0.73, large effect) •Significant gain with individual therapy (p < 0.001, d = 0.54, medium effect) 2. Sentence completion test of expressive vocabulary •Significant gain with group therapy (p = 0.004, d = 0.38, medium effect) •Gains did not reach significance with individual therapy 3. Analogies test of expressive vocabulary. No gains reached significance 4. Sentence comprehension test •Significant gain with group therapy (p = 0.02, d = 0.41, medium effect) •Significant gain with individual therapy (p < 0.001, d = 0.57, medium effect) Between group 1. Picture naming test. Gain for group therapy significantly greater than control group gain (p = 0.039) 2. Sentence completion test. No significant between-group difference 3. Analogies test. Gain for individual therapy significantly greater than control group gain (p = 0.01) 4. Sentence comprehension test. Gain for individual therapy significantly greater than control group gain (p = 0.039) |
Change from post-test to follow-up not reported, only pre-test to 4-month follow-up | High quality |
| Best et al. (2018), UK | Randomized control trial Control: 5 males & 4 females with DLD (aged 6; 3–8; 7) | 6 males & 5 females diagnosed with DLD as part of the study (age 6; 0–7; 8) | Word webs for combined phonological & semantic approach No other intervention accessed | Weekly 30 min sessions for 6 weeks Total: 180 min/3 h 25 target words, multiple presentation |
Provider: University SLT Mode: Face-to-face individual sessions in English Location: Mostly room in mainstream school | Within and between group pre-post comparison using a researcher-created picture-naming test of target words to assess expressive vocabulary | Between group •Significantly greater gain for therapy group than control group on target-words (p < 0.0001, d = 2.30, large effect), no significant difference on control words | Not measured | High quality |
| Best et al. (2021), UK | Randomized alternating treatment crossover design with 6-week washout | 12 males & 8 females diagnosed with DLD as part of the study (age 6; 4–8; 8) | Word webs for phonological versus semantic approach No other intervention accessed | Weekly 30 min sessions for 6 weeks per approach. Total: 180 min/3h 50 target words, 25 per approach, multiple presentation |
Provider: University SLT Mode: Face-to-face individual sessions in English Location: Mostly room in mainstream school | 1. Within group pre-post comparison using a researcher-created picture-naming test of target words to assess expressive vocabulary 2. Outcomes according to language profile |
1. Within group •Significantly greater target-word gain for semantic therapy than phonological therapy (p = 0.014, d = 0.489, medium effect) •No significant order effects or change in control words 2. Outcomes according to language profile •Children with semantic & phonological needs (n = 11): 3 children showed significant gain from semantic intervention only, 2 children from phonological intervention only, 5 children from both interventions, 1 child showed no significant gain from either intervention •Semantic needs (n = 6): 4 children showed significant gain from semantic intervention only, 2 children showed no significant gain from either intervention •Phonological needs (n = 3): 2 children showed significant gain from phonological intervention only, 1 child showed no significant gain from either intervention |
Loss in gains at 6-week follow up | High quality |
| Ardanouy et al. (2023), Switzerland | Pre-post comparison | 8 French-speaking children with existing diagnosis of DLD (age 6–10 years, gender unknown) | Combined phonological & semantic approach with context cues No other intervention accessed | 5 months of 45 min session per week. 4 sessions per theme covering 4 themes (sports, animals, vegetables, & school materials) Total: 840 min/14 h 60 target words, 15 per category, multiple presentation |
Provider: University SLT supported by Educational Psychologists Mode: Face-to-face group sessions in French Location: Specialist clinic | Within group and individual pre-post comparison using a researcher-created picture-naming test of target words to assess expressive vocabulary. Target words were grouped by category | Within group •Veg: Significantly greater gain for target words than control words (p = 0.01, r = 0.89, large effect) •Animals: Significantly greater gain for target words than control words (p = 0.01, r = 0.89, large effect) •Sports: Significantly greater gain for target words than control words (p = 0.01, r = 0.89, large effect) •School: Significantly greater gain for target words than control words (p = 0.02, r = 0.84, large effect) Individual level •Veg: Significant gain for 6 out of 8 children (p < 0.05) •Animals: Significant gain for all children (p < 0.05) •Sports: Significant gain for 7 out of 8 children (p < 0.05) •School theme: Significant gain for 4 out of 8 children (p < 0.05) •Control words: no significant change | Veg: no change at 1.5-month follow-up Animals: no change at 3-month follow-up Sports: loss in gains at 4.5-month follow-up |
Medium quality |
*Based on JBI quality appraisal rating (see Appendix A).
LI, Language Impairment; SLI, Specific Language Impairment; DLD, Developmental Language Disorder.