Digital books, adult mediation, and language and emergent literacy. A literature review

The role of enhancements

Digital books —also known as e-books or book apps— are books accessible through screen-based technologies (Kucirkova, 2019) and are characterised by enhancements that “improve” the reading experience, making it different from that of printed books. These are multimedia or interactive resources that complement or expand the content of the text, or that support the reading experience. These include background sounds, animations, hotspots (e.g., when touched, they activate sounds or animations) and games that motivate the reader (Bus et al., 2020).

These enhancements have been an important part of the debate on the influence of reading digital books in early childhood. According to Labbo and Kuhn (2000), enhancements that are consistent with the story support comprehension and retelling, while those that are not related to children’s passive viewing and the production of non-cohesive retellings. Fifteen years later, a meta-analysis (Takacs et al., 2015) proposes a finer distinction: multimedia and interactive features. It concludes that the former (e.g., animated images and sound effects) are beneficial for children’s comprehension and vocabulary, while the latter (e.g., games and dictionaries) are distracting because children must simultaneously listen to the narration of the story while interacting with an element on the screen, which may not be directly related to the content of the story. A subsequent review conducted by Reich et al. (2016) agrees that animations and games can be distracting elements that hinder learning, as can sound effects. Nevertheless, Kucirkova (2017) points out that the distinction between multimedia and interactive items is problematic because in some cases it can be blurred (e.g., an animation can be activated by touching the hotspot), which tests the scope of the results of Takacs et al. (2015).

A subsequent meta-analysis (Furenes et al., 2021) distinguishes between two types of enhancement: those that promote interest and enjoyment in reading for aesthetic purposes; and those that focus on the narrative plot for learning purposes. It concludes that enhancements are fundamental to understanding the text, since studies in which the digital book differs from the printed book only in terms of digitisation show lower scores for the digital version; on the other hand, those that use enhancements for learning purposes are more beneficial than the printed book. Additionally, it determines that dictionaries do not contribute to comprehension, but they do have an effect on vocabulary acquisition.

The classifications indicated appear to be based on different criteria: design (e.g., auditory/visual); the degree of interactivity of the enhancements (multimedia/interactive); and the objectives for which they were designed (aesthetic/learning). Therefore, the enhancement of digital books should be systematised from a broader perspective, allowing us to recognise what resources exist; what skills they could be impacting; and under what study conditions and instructional procedures they have been observed, in order to guide decision-making for the development of digital books aimed at early childhood.

Adult mediation

Another relevant dimension in the discussion has been the role of the adult mediator, who supports the child during shared reading (Grolig, 2020). The review by Reich et al. (2016) concludes that adults tend to talk more about the device than the content during shared reading of digital books and that the presence of an adult improves comprehension, language development and print awareness. A meta-analysis by Takacs et al. (2014) compared children’s word learning and comprehension with digital books versus printed books with and without adult assistance. It determined that there were no differences between digital and printed books in terms of children’s comprehension and vocabulary when an adult was present; likewise, when digital books incorporated multimedia features consistent with the narrative, they were more beneficial than printed books. Therefore, it concludes that some of these features provide scaffolding similar to that provided by an adult.

The meta-analysis by Furenes et al. (2021) recognises that adult mediation during the reading of printed books was more effective than the enhancements included in digital books for children’s independent reading. As for this discussion, a meta-analysis by Kucirkova (2019) points out that the superiority of parental mediation during the reading of printed books and the quality of the linguistic results obtained by children could be influenced by parents’ preference for this type of book and their resistance to digital books.

In the studies mentioned, the mediating role of the adult seems to be based on the assumption that it is replaceable in the child’s independent reading skill. However, it is necessary to analyse whether the research conducted in recent years is operating on this assumption. Therefore, it is necessary to systematise how their role in reading digital books is being assessed and what support they are being offered in the interventions. The type and quality of instruction provided to adults during the intervention may impact their performance as mediators.

Consequently, although previous reviews have addressed the impact of digital books on children’s comprehension and vocabulary, as well as the role of adult mediation in these skills, there has been insufficient exploration of which dimensions of mediation have been studied and what other language and emerging literacy skills these books might contribute to. Similarly, other factors that could influence the results have not been studied in detail, such as the enhancement included in digital books, the study conditions in which the subjects participated, and the instructional procedures of the interventions. Therefore, a scoping review (Munn et al., 2018) was conducted, guided by the following questions:

Item search and selection

Between September and December 2022, items were searched for in the Web of Science (WOS) and Scopus databases that had been published between 2012 and December 2021. A search range of ten years was established from the start of the search, considering the years of greatest research development in the field according to WOS. Different combinations of the following words were used: digital literacy, digital practices, digital book, e-book, electronic book, young children, toddlers, preschoolers, preschool education, kindergarten, language.

The results yielded 121 articles in WOS and 100 in Scopus. At this stage, 86 articles from WOS and 7 from Scopus were withdrawn because, although they addressed issues related to digital literacy, they did not develop interventions based on digital books that would allow for the observation of effects on mediation or on children’s language skills and emerging literacy.

More specific filters were then applied to analyse the 128 articles obtained in the previous step, and the following records were excluded: duplicates (=1); theoretical and literature reviews (=10); those involving children in grades higher than or equal to first grade (=13); unrelated to language and emerging literacy (=22); from populations with atypical linguistic-communicative profiles (=21); involving bilingual, multilingual subjects and those oriented towards second language teaching (=10); focused on educator performance and classroom interventions (=18); on literacy games that are not in book format (=3); observational studies on home literacy environments that did not involve interventions based on digital books (=4); that did not use books available in tablet, smartphone, iPad or computer format (=1). It should be noted that research on atypical children (e.g., autistic children) and bilingual children was not included in order to exclude variability related to their linguistic or communicative performance. In total, we got 25 items.

To expand the search, the snowball strategy was used. Papers published by the most cited authors in the field were reviewed. Next, the bibliographic references of the 25 filtered articles were examined to find studies that may not have been identified using the keywords. Seven articles were collected using this strategy. A total of 32 articles were analysed; 50% were conducted in the United States; 13% in Canada and Israel respectively, and 24% in Europe (table 1).

Analysis of the articles

All analyses were performed by the first author and then reviewed and agreed upon by the second author at all stages of the process. Thematic regularities were discovered through categorical analysis to answer the questions. Fourteen articles answered question 1; 31 answered question 2; and 13 answered both questions 1 and 2 (table 1).

Figure 1Difference between basic LD (Ldb)/enhanced LD (LDe) with some multimedia resources subject to experimental conditions 

Adult mediation

To contextualise the results, the enhancements identified in the studies linked to this review question are described (table 2). The most common enhancements in the digital books used in this study group are those that support knowledge of the printed text (n=11) and the presence of audio narration (n=12). In studies that employ highlighting, this accompanies the audio narration, which could favour the link between phonological processing and the printed code (e.g. Korat & Segal-Drori, 2016). Next, we count the studies that used digital books with animations (=10), audio resources (=7) and hotspot (=6) to bring elements of the story to life; support understanding of the narrative plot; communicate the emotional states of the characters; or access phonological knowledge of the word. Finally, there are studies that used digital books with dictionaries (=3), personalisation (=3) and focus (=1).

As for adult mediation (table 3), 12 studies reported results on the interactive dimension of adult input; 5 on the conceptual dimension; and 2 on the linguistic dimension. The experimental studies compiled subject the study subjects to different study conditions (table 4) to systematise the effects of digital books on adult mediation in each of these dimensions. The most common are between digital and printed books (=8) and between basic and enhanced digital books (=6).

In terms of printed books versus digital books, five studies report that when using digital books, adults tend to praise, encourage, and focus more on children during reading than when using printed books (e.g., Eggleston et al., 2021; Korat and Segal-Drori, 2016). Similarly, five studies found favourable results for the interactive dimension when using printed books over digital books, including more speech expansion and more interactions (e.g., Eggleston et al., 2021; Guevara et al., 2021; Korat & Segal-Drori, 2016). Although this pattern of results appears contradictory, it is important to note that the variables used in the studies are diverse and that instructional procedures could influence the results, as explained in the following paragraph.

Analysis of the instructional procedures of the group that compared printed books versus digital books (table 5) reveals that the two studies that used digital books with recommendations for adults to ask questions or make comments to children during reading obtained favourable results over printed books for adult mediation in interactions (Guevara et al., 2021) and in helping children understand the text and learn the printed word (Korat et al., 2013). In contrast, studies that reported favourable results for printed books only used instructional procedures such as instructions for use and book delivery.

When studying the three dimensions of interactivity, language and concept, it has been found that adults tend to talk more with their children about the story, the structure of words and their meaning when using digital books than when using printed books (e.g. Korat et al., 2013; Rvachew et al., 2017).

As for the comparison between basic and enhanced digital books, five of the six studies in this group report favourable results for enhanced digital books, particularly in terms of interactivity (Korat and Segal-Drori, 2016; Munzer et al., 2019a; Troseth et al., 2020) and conceptual understanding (Korat and Shneor, 2019; Korat et al., 2014). In the studies, the procedure of providing instructions for use predominates (=5), with the exception of Troseth et al. (2020), which uses book delivery, but includes an enhancement consisting of a character inserted into the digital book to encourage parents to talk to their children by providing dialogic reading strategies during reading. Only one study reports results more favourable to the basic digital book (Munzer et al., 2019b). It is striking that even though in this study the basic digital book differed from the enhanced digital book in terms of a group of enhancements (audio improvements, animations, and hotspots) and not just one of them, the basic book performed better.

Additionally, studies by Korat et al. (2013; 2014); Korat and Segal-Drori (2016), and Korat and Shneor (2019) explore the role of adults in enhanced digital books. Their findings indicate that enhancements aligned with the content of the story and those that favour the conceptual dimension of mediation —such as a dictionary— can encourage adults to effectively support children while reading digital books. In these studies, the condition of maximum effectiveness for the child is LDe with adult support. It should be noted that only Korat et al. (2013) and Korat and Segal-Drori (2016) use procedures such as reading recommendations and training outside the book, which is why the role of enhancement materials, particularly dictionaries, seems to be fundamental in improving the quality of adult mediation and, along with it, children's language skills.

Children’s skills

The enhancements (table 6) most commonly used in digital books in this study group are audio narration (=28) and those that support knowledge of the printed text (=22). Secondly, there are animations (=20), hotspots (=17) and audio resources (=13), such as background music or sounds associated with objects or characters in the story. Then there is the use of static images which, beyond illustrating the story, enrich specific aspects of it (=6). Finally, research reports the use of more specific resources in e-books, such as elements that support vocabulary knowledge (=4) and personalisation (=3).

With regard to the influence of digital books on children’s skills (table 7), studies focused on examining their influence on children's lexical-semantic skills (=15) and discourse comprehension (=11). Six studies were then identified that addressed pragmatic skills; five addressed reading attention; and four addressed skills related to knowledge of the alphabet. A smaller number addressed behaviours related to the use of digital books (=3); phonological skills (=2); and discourse production (=3). Nearly half of the studies (=15) assessed more than one skill.

With regard to study conditions (table 8), 16 studies compared groups that read digital books versus printed books. In this group, nine point to favourable results for digital: Four studies point to support for lexical-semantic skills (Korat et al., 2013; O’Toole and Kannass, 2018; Strouse and Ganea, 2017a, 2017b); 1 to comprehension (Courage et al., 2021); 1 to pragmatic skills (Strouse and Ganea, 2017b); 1 to alphabetical knowledge and awareness (Rvachew et al., 2017); and 2 to phonological awareness (Korat and Segal-Drori, 2016; Korat et al., 2013). Analysis of the instructional procedures (table 9) in the studies favourable to digital books shows that five used independent reading by the child with audio narration support and, within this group, three gave instructions to the child; one used prior familiarisation of the child with the digital book; and one did not give any instruction. In the remaining four studies in the group favouring digital books, an adult close to the child or a volunteer did the reading, and in three of these, the children received some kind of instruction; in contrast, in this subgroup, the children did not receive any instruction.

Among the research studies that compared digital books with printed books, with favourable results for the latter (=7), are those that reported findings in favour of knowledge and literacy skills (Deasley et al., 2016; Willoughby et al., 2015); pragmatic skills (Munzer et al., 2019b; Richter & Courage, 2017); discourse comprehension (Reich et al., 2019); print knowledge (Xu et al., 2019) and general linguistic ability (semantic, morphosyntactic and pragmatic; Guevara et al., 2021). In this group, five studies used independent reading by the child with audio narration, and two used a parent as the reader. In the group that uses audio narration, only two give instructions to the child; in the group where parents participate, the child receives no instruction.

Among the studies that employed more specific group study conditions were those that compared children's performance after reading a basic digital book and an enhanced digital book (n=12). Nine studies report favourable effects on enhanced digital book conditions, with six of them pointing to positive results for semantic skills (Korat et al., 2014; Korat & Segal-Drori, 2016; Korat & Shneor, 2019; Smeets & Bus, 2012; 2015; Takacs & Bus, 2016); three for comprehension (Dore et al., 2018; Sarı et al., 2019; Takacs & Bus, 2016); and 1 for phonological skills and knowledge of the alphabet (Korat & Segal-Drori, 2016). Among the enhancements studied to improve lexical-semantic ability are dictionaries, animations, and vocabulary questions; among those aimed at comprehension are audio narration, animations, and visual and sound effects consistent with the story. The interactive feature that reveals the phonological structure of the word was an enhancement that promoted the children’s phonological awareness.

Regarding the instructional procedures used in studies that employed enhanced digital books and found favourable effects on lexical-semantic skills, three used independent reading by the child with audio narration and delivery of the device without any instruction; one used instruction for both the mother and the child; and one used instruction for the adult only and no instruction for the child. In contrast, all studies that found favourable effects of enhanced digital books on comprehension used independent reading by the child, and only one gave instructions.

Of the six studies that used adult-supported versus unsupported conditions, five revealed favourable results for the supported condition in lexical-semantic skills (Korat & Segal-Drori, 2016; Korat and Shneor, 2019; Korat et al., 2013; 2014), discourse comprehension (Dore et al., 2018), and children’s phonological awareness (Korat et al., 2013). An adult caregiver participated in all of these studies, whereas the only study in which an adult researcher participated (O’Toole & Kannass, 2018) determined that the child learned more words from the digital book without support and with an audio narrator than from the experimenter reading aloud. In this latest study, the child was familiarised with the digital book beforehand; in contrast, in the remaining studies, three used instructions for use, one used reading recommendations, and one used training.