Table 2.

Overview of included works. NIH, National Institutes of Health; IT, information technology; GPS, Global Positioning System.

author(s)	country	article type	type of research	total sample size	compared with young adults	compared with learning alone	relationship with co-learners	materials	outcomes
Cheng & Strough [84]	United States	research article	randomized experimental studya	97	Y	Y	familiar	everyday problem-solving task	pairs were more accurate than individuals. Younger adults were faster and more accurate than older adults
Crompton [82]	United Kingdom	PhD thesis	non-randomized experimental study	48	Y	N	familiar, unfamiliar	adapted version of Map Task	no effect of age group or familiarity. Younger adults did have improved delayed recall
	United Kingdom	PhD thesis	non-randomized experimental study	24	N	N	perceived human versus computer partner	adapted version of Map Task	older adults modified their interaction when learning with a human or a computer. Older adults recalled fewer details of routes learned with the computer partner and found the learning experience more difficult
Crompton & MacPherson [85]	United Kingdom	research article	non-randomized experimental study	24	N	N	perceived human versus computer partner	referential task/Barrier Task	participants in the computer condition were slower, took fewer turns, and recalled less
Crompton et al. [86]	United Kingdom	research article	non-randomized experimental study	48	Y	N	familiar, unfamiliar	referential task/Barrier Task	older adults’ performance became indistinguishable from younger adults over time, no effect of familiarity
Derksen et al. [7]	United States	research article	non-randomized experimental study	68	Y	N	familiar	referential task/Barrier Task	older adults' performance became indistinguishable from younger adults over time
Filer & Scukanec [87]	United States	research article	non-randomized experimental study	8	Y	N	unfamiliar	referential task/Barrier Task	younger women used fewer words, turns, and had fewer errors than older adult women
Gould et al. [88]	United States	research article	non-randomized experimental study	60	Y	N	familiar, unfamiliar	referential task/Barrier Task	younger adults performed better overall (including number of words, turns, and optimal descriptions) compared to older adults, with no effect of familiarity
Hupet et al. [89]	Belgium	research article	non-randomized experimental study	40	Y	N	unfamiliar	referential task/Barrier Task	older adults’ performance improved but not to the extent that younger adults' performance did
Kannampallil et al. [81]	United States	research article	randomized experimental study	144	N	N	unfamiliar	medication schedulers	older adults created more accurate medication schedules when using a structured aid, with no difference between structured and unstructured aids when considering medication complexity
Margrett et al. [90]	United States	research article	non-randomized experimental study	22	Y	N	familiar	adapted version of VW task	couples actively worked together, most often tutoring each other. Middle-aged adults outperformed older adults
Margrett & Willis [91]	United States	research article	randomized experimental study	98	N	Y	familiar	multi-week training on inductive reasoning strategies	receiving training is generally beneficial, there was no difference in accuracy between working alone and working together
Morrow et al. [83]	United States	research article	randomized experimental study	96	N	N	unfamiliar	medication scheduler	aids are associated with higher accuracy, especially when the medical scenario is complex, compared to an unstructured aid (pen and paper) or no aid
	United States	research article	randomized experimental study	64	N	N	unfamiliar	medication scheduler	participants were more accurate when using the medication scheduler, but there was no difference in speed
Peter-Wight & Martin [53]	Switzerland	research article	non-randomized experimental study	141	N	Y	familiar	Black Box task	participants' performance was better when working collaboratively versus working alone
Rodrigues et al. [92]	United States	research article	non-randomized experimental study	32	Y	N	familiar, unfamiliar	referential task/Barrier Task	participants became more efficient over time, regardless of age and familiarity. Younger adults were more efficient in communicating with a familiar partner, older adults were more efficient in communicating with an unfamiliar partner
Seah et al. [79]	Canada	research article	non-randomized mixed method study (quantitative and qualitative)	50	N	N	largely unfamiliar	bingo nutrition and health game	participants significantly improved their knowledge of health and nutrition, had a more positive attitude towards digital games, and their social connectedness increased. Common themes in the interviews consisted of social connectedness and knowledge of technology, health and nutrition
Saczynski et al. [93]	United States	research article	randomized experimental study	96	N	Y	familiar	multi-week training on inductive reasoning strategies	individual and collaborative training groups did not differ in performance, except when both completing a collaborative recall test (in which individuals working together did worse)
Sayago et al. [78]	United Kingdom, Spain	research article	ethnographical study with semi-structured interviews	420	N	N	largely unfamiliarb	multi-week training on basic computing skills	during initial learning, participants mostly worked with the same partner. Participants found interacting with unfamiliar peers difficult due to different strategies or strategies had to be created and agreed
Vazquez et al. [94]	United States	research article	randomized experimental study	466	N	Y	largely unfamiliarb	tutorial on searching for health information online (NIH)	no effect of collaboration in terms of satisfaction or performance. Previous IT experience may mediate the relationship between learning outcomes and learning methods
Vrkljan [95]	Canada	research article	non-randomized experimental study	44	N	N	familiar	using a GPS system	couples less experienced with technology had higher levels of assistance, mostly supportive. Couples more experienced with technology provided less assistance but the assistance that they did provide was more directive
Vrkljan [96]	Canada	research article	non-randomized experimental study	40	N	N	familiar	using a GPS system	couples more experienced with technology made fewer errors overall, performed each task at a faster rate, and provided less assistance
Wei et al. [97]	Canada	research article	qualitative research	22	N	N	familiar	semi-structured interview and open-ended questions	older adults often search online for daily tasks, interests, and curiosity. The latter is often to settle a disagreement or to discuss a topic together
Wood et al. [80]	Canada	research article	non-randomized experimental study	64	N	N	largely familiarb	training sessions to develop computing skills	collaborations were considered helpful and effective, and participants were more involved
Xie [103]	United States	research article	randomized experimental study	124	N	Y	largely unfamiliarb	tutorial on evaluating Internet health information (NIH)	performance improved regardless of condition or familiarity
Xie [104]	United States	research article	non-randomized experimental study	172	N	N	familiar, unfamiliarb	tutorial on searching for health information online (NIH)	performance improved regardless of familiarity
Xie [105]	United States	research article	randomized experimental study	146	N	Y	largely unfamiliarb	tutorial on helping older adults search for health information online (NIH)	performance improved regardless of collaboration or learning design
Yoon & Stine-Morrow [98]	United States	research article	non-randomized experimental study	48	Y	N	unfamiliar	referential task	older adults found it more difficult to identify the source of a description and adjusted their descriptions less when working with a naïve partner compared to younger adults
Zhang et al. [99]	Canada	research article	observational study	22	N	N	unfamiliarc	Wii Sports Resort games	older adults learn through questions and feedback of their younger partners, such as pointing out errors or explaining concepts

^aIndicates studies that are largely randomized but have made minor changes or specifications that were not random.

^bIndicates study designs that were largely unfamiliar or unfamiliar, but also had some participants included that did not fit this design.

^cBoth younger and older adults were involved in this study. However, the younger adults were involved as a guide and their learning performance was not assessed. As such, this study is not included in the younger versus older category.