Early research on digital tabletops focused on specific issues like the use of orientation, space, and interaction techniques. Applications developed in these initial explorations of the design space were rather simple and focused at specific interface issues. From 2006 onwards, contributions at the application level began to emerge, some of which specifically investigated learning support and problem solving using digital tabletop interfaces (Piper et al., 2006; Rick and Rogers, 2008; Rick et al., 2009a; Piper and Hollan, 2009; Morgan and Butler, 2009; Do-Lenh et al., 2009; Fleck et al., 2009). All these contributions motivated the use of tabletops in terms of their unique char- acteristic of bringing computer support to face-to-face style of collaboration, the higher levels of engagement of users (compared to other media), and the potential benefits of new types of educa- tional applications based on tabletops. However, there have been relatively few studies that have incorporated explicit educational goals, grounded in pedagogical theory, and conducted in realistic
settings. Rather than focusing on the sorts of issues educational practitioners and researchers are concerned with, such as comprehension and higher level thinking skills, tabletop learning research has to date tended to be exploratory in nature, focusing on specific applications, such as layout design and the physical manipulation of virtual objects (Piper and Hollan, 2009; Do-Lenh et al., 2009).
Rick et al. (Rick and Rogers, 2008; Rick et al., 2009b) adapted a desktop learning application to a multi-touch surface. In their work, they used learning theory to motivate the transformation from desktop to tabletop, guide the design process, and inform the evaluation. Their collaborative learning application (DigiTile) aimed at helping children with age range (9-12) to collaboratively learn about fractions. The implementation used a small (81cm diagonal) DiamondTouch table (Di- etz and Leigh, 2001) and required its two users to sit next to each other at one side of the table. Their system used a standard menu bar at the top and a set of replicated toolbars on each side with a shared area in the middle. The design targeted a number of important educational con- cepts, such as allowing for different perspectives of the data, supporting learning by doing, and encouraging collaboration. With respect to collaboration, they experimented with two different ways of allocating resources between participants: shared resources with each child having a full set of the required resources on her side, or split resources with each child having only half of the required resources. The evaluation of the system was based on pre- and post-tests. The results showed significant improvement in knowledge about fractions after using DigiTile, but no signifi- cant difference between the different resource allocation strategies. Rick et al. (2009b) reported an interesting observation related to the distribution of work on multi-touch surfaces (refer to section 2.2.3.7), where they observed that even though parallel interaction was permitted in DigiTile, the more difficult the task was, the more the children worked jointly on solving it. While in their work Rick and Rogers (2008) specifically raised a question regarding adapting applications to new me- dia, “could the new application benefit significantly from the move to the new interface?”, their implementation still had a number of similarities to a desktop setting with its shoulder-to-shoulder style of interaction, fixed horizontal orientation, and a menu bar for initiating commands. Allow- ing for simultaneous direct touch interaction on a horizontal surface, does enforce a different style of interaction than that with a single (desktop) computer display, but the applications still leaves many of the tabletop characteristics (the new interface) un-utilized.
Piper et al.’s (2006) work on SIDES targeted a very specific audience, adolescents with As- perger’s syndrome in social group therapy. The aim of the application was to encourage the practice of effective group work skills, such as negotiation, turn-taking, active listening, and per- spective taking. This involved four players seated in fixed positions around a tabletop each with a similar set of voting tools that generate action level events only when all of the participants pressed them simultaneously. Enforcing collaboration in this manner mitigated against individual decisions and encouraged social interaction. The pedagogical design was based on constructivist learning theory and on Vygotsky’s theory (Vygotski˘ı et al., 1978) that learning is a social process
with roots in social interaction. Through an account of an iterative design process starting with interviews, and moving to paper prototypes, Piper et al. demonstrated that such a tabletop game provided a motivating experience which helped member of this challenging user group learn ef- fective group work skills. When the computer enforced the coordination rules, the emphasis of the therapist’s role changed to being one of helping the clients reflect on the activity and tie it to their experiences in real life. While the application was carefully designed to utilize the affordances of the technology in coordinating collaboration, generalizing the reported observations must be done with care due to the specific nature of the targeted audience.
Morgan and Butler (2009) assessed the potential impact of multi-touch technology on cogni- tion and learning using three theories: social-cultural theory (for dialog and collaborative layer); distributed cognition (DC) theory (for shared digital workspace layer); and situated cognition (for the cognitive activity context). In DC, they considered the tabletop as the mediating artefact be- cause it holds a representation of the current state of the solution to the problem and as in Hilliges et al. (2007), they referred to the table’s characteristic of preserving this state and thus freeing cognitive load from the students. The preservation of the representation state is, however, not the only thing to shape the cognitive activity, but also the tools available and the structures that control the collaborative process. Mediating artefacts can be considered as tools that regulate activity by organizing a division of task and coordinating collaboration. Morgan and Butler proposed con- cept mapping and story boarding applications for the purpose of their investigation. The proposed designs were based on the concepts of working from fixed positions, the division of tasks, and roles assignment. While highlighting the importance of identifying students to allow for monitor- ing contribution, Morgan and Butler also discussed the difficulties in doing that with multi touch tables and suggested solutions based on area of interaction and the division of tasks and roles.
Do-Lenh et al. (2009) investigated the effect of tabletops with tangible interfaces on collabo- rative learning. They compared a concept mapping task performed around a traditional computer display using one mouse/keyboard for input, with a tabletop application that supported tangible interaction, and measured the differences between individual and group learning gains. Based on pre-tests and post-tests, their results showed no significant effect on individual learning gains, but also showed that groups using the traditional computer setting learned significantly more from their partners than in tabletop setting. Their analysis of the results showed that the traditional computer setting with its one point of access helped in transferring knowledge from more achiev- ing to less achieving students, and thus such a setting might be preferable in cases where the level of initial knowledge between group members is significantly different. They justified this in that, for tabletop conditions, high-expertise students failed to dominate the conversation and thus had less positive effect on their partners. This indicates that the equal level of participation afforded by tabletops, if not utilized correctly, may have negative effects on group learning in groups with vari- ant levels of initial knowledge. On the other hand, such equal level of participation is considered to be an advantage if the goal is to reduce the effect of dominant students. Finally the analy-
sis showed that collaboration in tabletop condition was mixed between explanation, group work, and individual work, while in computer case there was a division of roles and more coordinated collaboration.
Piper and Hollan (2009) focused on tabletops as a studying tool for pairs of students (under- graduates in this case) and compared it to studying on paper. Their main goal was to investigate two issues: the effect of large, horizontal, multi-user displays on cognition and social activities in shared studying environments; and the pedagogical benefits gained from tabletops beyond the motivating context that they provide. Piper and Hollan distinguished their work from others by firstly focusing on the effect of using digital tabletops versus paper on study practices, like partic- ipation and cooperation, rather than focusing on the application, which was intentionally made as simple and as basic as possible; and secondly by studying the interaction over multiple-sessions to observe behavioural patters over time and ensure that the observed behaviours are not results of first time use. With regard to the second point, they brought into focus the effect of novelty of the medium and observed its effect in causing much off-task behaviour; and pointed out a short- coming of other research that made conclusions based on first-time encounter with such a new medium. As mentioned, the application used was very basic and mirrored the tools that students need while reading from paper. Each student had her own draw and erase buttons in addition to some commands in a shared menu. Their findings showed that students with paper material made more detailed notes and worked serially, while students with the tabletop display repeated activ- ities more, worked in parallel, and performed better on exams. They also stated the potential of tabletop technology in logging students interaction during the session for later use by the teacher or the students, and the potential of providing scaffolding by the application. Finally, and although their task involved two users only, they indicated that that the size of the DiamondTouch table used (81cm diagonal) proved to be rather small.
Both Do-Lenh et al. (2009) and Piper and Hollan (2009) used basic applications for the table- top versions that, other than allowing parallel interaction, were not specifically designed to utilize the affordances of the technology, and did not arise from an iterative design process that might have addressed any observed shortcomings. Conclusions based on such limited implementations cannot be generalized as comments on the potential of tabletop technology to support collabo- rative learning, but can provide useful insights on some aspects of such support (those that are particular to the implementation).
The OurSpace application (Fleck et al., 2009; Rick et al., 2009a; Harris et al., 2009) was implemented and used to investigate different aspects of collaborative interaction and collaborative learning for children around tabletops. While the focus in Rick et al. (2009a) and Harris et al. (2009) was on issues of contrasting single touch and multi touch (see Section 2.2.3.7) and the use of space, the focus in Fleck et al. (2009) was on examining the coupling of verbal interaction and physical action in collaborative learning tasks around tabletops. The OurSpace application was implemented on a DiamondTouch table (81cm diagonal), and was designed to allow groups
of three children (aged 7-10) to plan their classroom layout. The hardware and the software design forced the children to work from fixed positions around three sides of the table. The investigation uncovered that physical and verbal aspects work in parallel during collaboration and highlighted the importance of gesturing while talking for the learning process. They also found evidence that such physical disagreements as blocking and undoing each others work, which might appear as negative behaviour, could actually lead to learning when interpreted as parallels of verbal negotiation. In light of these findings, Fleck et al. stated that quantitative comparative studies (e.g Do-Lenh et al., 2009; Piper and Hollan, 2009; Rick et al., 2009b) may miss some aspects of the interaction that are significant to the learning process. They also argued against designs that enforce territoriality and restrict access to certain resources as these will reduce the positive learning outcomes that may result from physical interference. Finally, with regards to single versus multi-touch input, they stated that even when children were allowed unrestricted parallel interaction, collaborators could still manage periods of effective collaboration. These results emphasized the important context that the tabletop setting provides to collaborative learning when it is designed to provide unrestricted physical, visual, and auditory setting.
Among the issues discussed by Piper and Hollan (2009) is that of embodied cognition, that is the engagement of our bodies and how this might help, or constrain, how we reason about ab- stract concepts. They categorized the act of tracing an answer graph with a finger as embodied cognition, and their analysis showed that such a process could have attributed to the better results gained from interacting with tabletops due to the richer understanding and internalization of ab- stract concepts resulting from such embodied cognition. Fleck et al. (2009) also uncovered the importance of combining verbal with physical action around the table for collaborative learning applications and argued against enforcing restrictions in the form of fixed territorial design or limiting access to resources. Before that, Tang et al. (2006) highlighted the importance of using gestures while collaborating around traditional tables and the important role gestures play in col- laboration by adding to the content of the discussion. Despite such findings, all the settings in the reviewed research that targeted learning and problem solving assumed participants working from fixed positions accompanied by different levels of enforced territoriality and restricted access to resources, a limitation imposed either by the hardware (such as the case with DiamondTouch ta- bles), or by the case study design itself. Furthermore, while face-to-face style of collaboration is a distinguishing feature of tabletop interaction over shoulder-to-shoulder style of traditional SDG systems, the settings used in Rick and Rogers (2008), Piper and Hollan (2009), and Do-Lenh et al. (2009) required users to sit side by side to overcome problems of orientation or limited table size. This means that although findings from such studies can be generalized to other tabletop settings, questions remain as to the impact of the un-utilized benefits of using a shared space, freedom of movement around the table, and face-to-face interaction, particularly in relation to awareness of the actions of others.
A number of other researchers targeted educational aspects of tabletops for kindergarten chil- dren or early primary levels where the focus is on playing or learning basic skills, such as reading (Khandelwal and Mazalek, 2007; Sluis et al., 2004; Cappelletti et al., 2004). The problem space for children of this age differs from that targeting older students (Sluis et al., 2004).