Fostering awareness and collaboration in large-class lectures

For decades, higher education has been shaped by large-class
lectures, which are characterized by large anonymous audiences.
Well known issues of large-class lectures are a rather low degree
of interactivity and a notable passivity of students, which are
aggravated by the social environment created by large audiences.
However, research indicates that an active involvement is
indispensable for learning to be successful. Active partaking in
lectures is thus often a goal of technology- supported lectures. An
outstanding feature of social media is certainly their capabilities
of facilitating interactions in large groups of participants.
Social media thus seem to be a suitable basis for
technology-enhanced learning in large-class lectures. However,
existing general-purpose social media are often accompanied by
several shortcomings that are assumed to hinder their proper use in
lectures. This thesis therefore deals with the conception of a
social medium, called Backstage, specially tailored for use in
large-class lectures. Backstage provides both lecturer- as well as
student-initiated communication by means of an Audience Response
System and a backchannel. Audience Response Systems allow running
quizzes in lectures, e.g., to assess knowledge, and can thus be
seen as a technological support of question asking by the lecturer.
These systems collect and aggregate the students' answers and
report the results back to the audience in real-time. Audience
Response Systems have shown to be a very effective means for
sustaining lecture- relevant interactivity in lectures. Using a
backchannel, students can initiate communication with peers or the
lecturer. The backchannel is built upon microblogging, which has
become a very popular communication medium in recent years. A key
characteristic of microblogging is that messages are very concise,
comprising only few words. The brief form of communication makes
microblogging quite appealing for a backchannel in lectures. A
preliminary evaluation of a first prototype conducted at an early
stage of the project, however, indicated that a conventional
digital backchannel is prone to information overload. Even a
relatively small group can quickly render the backchannel discourse
incomprehensible. This incomprehensibility is rooted in a lack of
interactional coherence, a rather low communication efficiency, a
high information entropy, and a lack of connection between the
backchannel and the frontchannel, i.e., the lecture’s discourse.
This thesis investigates remedies to these issues. To this aim,
lecture slides are integrated in the backchannel to structure and
to provide context for the backchannel discourse. The backchannel
communication is revised to realize a collaborative annotation of
slides by typed backchannel posts. To reduce information entropy
backchannel posts have to be assigned to predefined categories. To
establish a connection with the frontchannel, backchannel posts
have to be stuck on appropriate locations on slides. The lecture
slides also improve communication efficiency by routing, which
means that the backchannel can filter such that it only shows the
posts belonging to the currently displayed slide. Further
improvements and modifications, e.g., of the Audience Response
System, are described in this thesis. This thesis also reports on
an evaluation of Backstage in four courses. The outcomes are
promising. Students welcomed the use of Backstage. Backstage not
only succeeded in increasing interactivity but also contributed to
social awareness, which is a prerequisite of active participation.
Furthermore, the backchannel communication was highly
lecture-relevant. As another important result, an additional study
conducted in collaboration with educational scientists was able to
show that students in Backstage-supported lectures used their
mobile devices to a greater extent for lecture-relevant activities
compared to students in conventional lectures, in which mobile
devices were mostly used for lecture-unrelated activities. To
establish social control of the backchannel, this thesis
investigates rating and ranking of backchannel posts. Furthermore,
this thesis proposes a reputation system that aims at incentivizing
desirable behavior in the backchannel. The reputation system is
based on an eigenvector centrality similar to Google's PageRank. It
is highly customizable and also allows considering quiz performance
in the computation of reputation. All these approaches, rating,
ranking as well as reputation systems have proven to be very
effective mechanisms of social control in general-purpose social
media.