Enhancing Classroom Lectures with Digital Sliding Blackboards Guido Roßling ¨
Christoph Trompler
Dept. of Computer Science Darmstadt University of Technology, Germany
Dept. of Computer Science Darmstadt University of Technology, Germany
[email protected]
[email protected]
[email protected]
Susanne Kobler ¨
Susanne Wolf
HDA Darmstadt University of Technology, Germany
HDA Darmstadt University of Technology, Germany
[email protected]
[email protected]
ABSTRACT Traditional blackboard-based lectures provide context on the sliding blackboards. Modern lectures incorporating video projectors typically do not provide this context. We describe a project that combines both approaches to provide context for “modern” lectures. We also discuss the benefits for educators and students. The software is sufficiently versatile to incorporate practically any software for content display.
Categories and Subject Descriptors K.3.1 [Computers and Education]: Computer Uses in Education—Computer-assisted instruction
General Terms Management
Keywords Digital Lecture Hall, VMB, Digital Sliding Blackboards
1.
Max Muhlh ¨ auser ¨
Dept. of Computer Science Darmstadt University of Technology, Germany
INTRODUCTION
The last years have brought an increasing interest in virtual universities and web-based learning. Many students essentially expect that part of the lecture content is offered online. In simple cases, this may be restricted to the lecture or exercise materials. In other cases, whole lectures are recorded and offered as a video stream.
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Despite these advances, a large part of the current learning process still takes place in lecture halls. One reason for this is certainly that placing extensive lecture materials online requires a significant investment of money, working time and data storage. We propose that there are two further reasons why not everybody wants to adopt the current trend. First, the necessary changes to the teaching and working style are significant, possibly without any direct tangible benefit for the educator. Second, lecture rooms support social interaction between students and between students and educators. This missing interaction is perhaps part of the reason why many students of distance education tend to be less motivated or engaged [7]. We believe that the lecture room as a focus for interaction will retain its importance. Our digitally-enhanced lecture room (“Digital Lecture Hall”, DLH) [3] aims to encourage educators to experiment with modern technologies without placing hurdles for them. Therefore, the DLH can more accurately be seen as an evolutionary step for lecture rooms than as a revolution. The DLH offers a wireless LAN (wLAN) infrastructure, multiple video projectors, a tablet for writing while facing the audience and video streaming for archiving the lecture or parts thereof. A Java-based software allows students to ask questions or send general comments. They can also evaluate the quality of the lecture and take part in knowledge tests or decision polls [4, 6]. The center piece of the DLH is our Virtual MultiBoard software, which offers extensive support for presenting content for both educator and students. The rest of this paper will focus on the VMB and its features.
2. WHY A DIGITAL BLACKBOARD? Several classroom aspects have been established over centuries or at least decades of use. One of the main staples of lecture halls is a blackboard. Often, lecture rooms have several sliding blackboards. The educator can easily spread long proofs or programs over several blackboards. Thus, the presence of multiple sliding blackboards provides both
a context for the current content and a “history” of the lecture notes. Students who get lost or are slow in taking notes clearly benefit from this. The introduction of overhead projectors and the common use of slides have mostly given this advantage away. Typically, the layout of the projectors prevents showing more than one slide at the same time. Some educators have developed their personal “stacking” technology for placing multiple slides side-by-side or on top of each other. Still, the output is usually less than satisfying. Currently, the “state of the art” in presentation technology is usually a video projector that presents slides. Typically, the slides are generated using Microsoft PowerPoint or similar presentation programs, or based on established typesetting software such as LATEX. When we compare video projectors showing slides with overhead projectors showing transparencies, the differences essentially touch on the material (digital versus printed) and the ease of changing the content. However, from the student’s point of view, there is little difference between a single colorful slide and a single transparency. The context of the current slide is lost. Approaches such as including an abbreviated table of contents on each slide cannot fully redress this. Most educators are probably familiar with the consequences of the loss of context. Students who feel “lost” usually lose track of the lecture, at least for a certain while. If lecture materials are available in printed form, the student may need time to locate the necessary information to understand the “current” content. Thus, by the time he or she returns from browsing the materials, the lecture has advanced and the student has missed additional content. If no printed lecture materials are available, the student may be ill-equipped to understand the rest of the lecture. The lack of context also makes it more difficult for the educator to compare different approaches. For example, only one algorithm can typically be shown on a slide or transparency. Therefore, comparing two different but related algorithms usually happens only verbally - or on a third slide showing only the comparison, but not the compared entities. Based on these short-comings, we have developed a software called Virtual MultiBoard. This software is geared to provide a “best of both worlds” approach between the classical sliding blackboards and video projector-based presentations. The lecture contents are presented within the VMB software and can be presented on multiple video projectors.
3.
THE VIRTUAL MULTIBOARD
The Virtual MultiBoard (VMB) provides screen management, annotation and recording functionalities. It enables the educator to present arbitrary applications and digitally displayable information on one or multiple projectors.
annotate the current display. Annotations are placed on a “glass pane” in front of the background to prevent unwanted interaction with the underlying software. The VMB contains two control screens for running applications. The first control screen typically contains the lecture materials, e.g. a PowerPoint presentation. The second control screen can contain arbitrary applications used within the lecture, for example algorithm animation tools such as Animal [5]. Switching the display between these components is accomplished with a single mouse click. Provided that network access is available, either via Ethernet or wireless LAN, additional interaction support can be used. This includes support for interactive quizzes and a front-end for handling student questions. Questions submitted by students are not shown automatically to prevent “fun questions”. However, a small display indicates to both educator and audience how many questions there are. This also gives feedback to the students that their question has reached the educator and now waits for his or her attention. The VMB includes a recording component which captures all changes in the working areas. The information gathered is stored locally, but can also be simultaneously transmitted or broadcasted. A player can be used to view the recordings. Playback is continuous and may be synchronized with an recorded video stream. Sophisticated navigation supports positioning on random events, times or contents. Distributed to the students as ToGather, the player mutates to a personal annotation tool. This lets students add their own annotations to a recorded or live lecture. The top line of the VMB window (1) contains five toggle buttons. Using these, the educator can activate or deactivate the following components of the VMB:
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3.1 Using the Virtual MultiBoard The VMB offers several operations to the educator. A novice user may wish to stick to simply holding a lecture. To do so, he or she need only start the VMB software together with PowerPoint or the presentation software used. Once VMB runs, the presentation content is simply dragged into a control area, as described below. As a next step, the educator can start annotating the materials. This is accomplished by selecting the appropriate pen from the tool bar and using either the mouse or a pen to
Figure 1: Educator’s View of the VMB
• lecture materials (3) contains sources for background material and an overview over the virtual screen regions otherwise not visible to the user (4). • the working area (5) is where the lecturer runs the actual presentation, for example by annoting slides (6), • displays - control the layout of the student display, as described in Section 4.1, • quizzes using a special interaction software described in [3], • and questions from the audience, submitted over a special feedback software using wireless LAN. Typically, most of the educator’s attention will be focused on the working area view (6). The VMB window itself is an application toolbar, which like the Windows taskbar consumes part of the primary desktop. The remaining desktop area can be consumed by any other Windows application. Figure 1 shows only the PowerPoint DualView slide presenter which can be launched under VMB (7). Other software can share this space at the lower half of the display. Of course, the VMB window can also be dragged to increase or decrease its size. To enhance the presentation, the VMB offers a configurable tool bar (2), as shown in Figure 2. The user can select which tools he needs in the lecture and so limit the range of commands for better usability. The bar shown in Figure 1 offers several features for display and annotation support. For example, the user can move existing annotations or add temporary annotations. A new page can be inserted with a selectable background: same as the current slide, plain white or the content of virtual display 1. Six annotation colors (red, green, blue, white, black or yellow) can be used for both lines or filled rectangles.
3.2 Technical Aspects The educator can choose between two presentation modes. The “clone screen” mode automatically shows the contents of the educator’s display. The “dual view” mode offers two different views, one “private view” for the educator and a “public view” for the audience. This is helpful for preloading content or accessing lecture notes which remain invisible to the audience. The dual view mode requires hardware support in the form of a graphics adapter supporting (at least) two output screens. Note that the VMB’s “dual view” mode is not identical to a standard dual view. The contents of the private and public view are usually not identical. The audience only sees the contents of the public view, typically the current slide. The VMB toolbar, shown in Figure 2, is only shown on the private view (except when the “clone screen” mode is active). The same is true for all windows which are not dragged into the lecture materials (Figure 1, (3)). Apart from the VMB toolbar, this concerns the descktop including all icons and any other window the educator may have opened, such as a Web browser or animation software. When using a dual view, the projection area may be outside the educator’s line of sight. He or she may therefore be unaware of possible display problems in the “public” view. Some applications like PowerPoint provide special dual screen presentation modes to compensate this problem. PowerPoint provides navigation, display of notes and a mirrored view of the second display contents on the private screen. This removes the need to actually keep an eye on the projection. Unfortunately, PowerPoint does not support annotations on the private screen, limiting its usefulness. The hardware and software requirements for running the Virtual MultiBoard are modest. The VMB requires Java 1.4 or later. The screen recording functionality for lecture note dissemination is currently only implemented for Windows 2000 or later. The VMB software is available free of charge. The software was designed for use on a pen-sensitive display, but can also be used with a mouse. If more than one video projector is used, a multi-monitor graphics adapter is also required, otherwise a dual view card is sufficient.
4. BENEFITS WHEN USING VMB The Virtual MultiBoard offers attractive benefits for both educators and students. As the concerns are different, we separate the discussion in two sections.
4.1 Benefits for Students
Figure 2: VMB tool bar
As stated in Section 2, one common cause for students to lose track of the lecture is the lack of context. Using the Virtual MultiBoard, educators can address this problem by providing context - without adding extra work for the educator. Figure 3 shows our fixed Digital Lecture Hall installation [3] in a lecture room with a capacity of about 150. One of the ceiling-mounted video projectors is visible, as well as a Smartboard on the right side of the display. The educator is currently working on the lecture materials through a pen-sensitive display. It is important to point out that multiple displays do not mean multiple or parallel topics. Rather, the additional displays cover a history of the preceeding contents, typically the last n slides. If the educator switches media during the lecture, the different content is reflected in the displays.
However, the display still only shows a “history” of actually presented content.
Figure 4: “Mobile” Installation of the Virtual MultiBoard Figure 3: “Static” Virtual MultiBoard Installation
Behind the lecturer, the lecture contents are projected to the wall. In the configuration shown in Figure 3, these consist of three slides. The slide on the left, shown slightly larger than the others, is the current slide. It is also shown on the Smartboard to allow for easier annotation. The other two slides are the two preceeding slides. The students thus always work in the context of the current and the two last preceeding slides. Students with a laptop or PDA connected to wireless LAN can also send questions to the lecture or take part in quizzes. Questions are visible only in the educator’s VMB interface. At the educator’s discretion, they can be turned off to avoid distraction - or switched to the main display for an open discussion [3]. Figure 4 shows a different set-up owing to technical and administrative issues. It was taken in a CS 1 lecture with more than 650 attendees in the auditorium maximum (most of the audience is outside the camera range). The large slide on the left side shows the current slide presented by the educator. The two preceeding slides are shown below each other on the right side. The auditorium maximum can hold more than 800 students. It is reserved for practically every lecture period throughout the week. Therefore, we could only use a “mobile” installation of our hardware. The table in front of the educator holds a pen-sensitive display used for controlling the presentation and annotating the slides. For better readability, a large plasma display was mounted on the cupboard holding our hardware. As writing on the plasma display meant turning away from the audience, the display was not used often during the lecture - annotations were mostly done on the pen-sensitive display. Annotations are attached to the slides and are thus part of the displayed “history”.
4.2 Benefits for Educators For the moment, we will assume that the educator has prepared PowerPoint slides for the lecture. We will then discuss how we can support other formats or even “classical” chalk-based lectures. At first glance, not much changes for the educator. Some
additional software – the VMB itself and a PowerPoint plugin – has to be started, but this is accomplished with a few mouse clicks. After the VMB software is running, the educator can access the VMB’s rich functionality in the main window, as shown in Figure 1. The PowerPoint plug-in automatically causes an update of the display when the slide is changed. Educators can also replace PowerPoint with any other software. The software can be started within the virtual desktop provided by the VMB or dragged into the VMB window. It can then be controlled normally. The slide-change catching mechanism has to be simulated by pressing the “next page” button whenever the display should be updated. In several cases, the manual page switch mode offers interesting chances for discussion. For example, software with only a single view can be “frozen” in different stages of execution. We experimented with this using the Animal algorithm visualization system [5]. While running an animation of doubly linked lists, we provided a running commentary on what happens and why. We then froze the animation in three different places to illustrate the (separately discussed) algorithms for inserting elements at the beginning, end or middle of a doubly linked list. Based on the different screen shots including source code, the students found it easier to see where the differences and common parts of the algorithms lie. Similar benefits are expected when other visualization software is used, such as JAWAA [1], JFLAP [2] or commercial tools such as MatLab. Finally, educators who are used to doing most of their work with chalk can still benefit from the VMB. They simply select an empty slide whenever the current slide is filled. Using the pen-sensitive display admittedly takes some getting used to, but is still a viable possibility.
5. EVALUATION The evaluation of the VMB was performed by two members of our university’s didactics and evaluation team. A formative evaluation was conducted over the course of a full semester. The evaluation used a combination of qualitative (interviews) and quantitative methods (paper and online questionnaires). The goal was to incorporate the results
during the actual follow-through of the lecture as part of its development. The questioned persons were mostly first semester students of the departments of computer science and business computer science. The students rated, among other things, how helpful presentation techniques were with respect to comprehensibility and success in learning. Presentation using the VMB was rated “more helpful” than more traditional techniques. Overall, the students rated the VMB very positively. 80% stated that they could follow the lecture contents well with help of the VMB. Especially the “history” function was judged very positively: approximately 75% of the students found it helpful to have smaller versions of the two previous slides next to the actual slide in use. Besides the general positive feedback, the students voiced some criticism and improvement possibilities. These points were mainly made with regard to the “annotation” function. Half of the students rated the annotations as helpful towards their comprehension. However, they also wished that annotations be used more sparingly. Slides become illegible due to excessive annotation use of the lecturer. Due to the progressive nature of the evaluation, suggestions of improvements from the students could be gathered and conveyed to the lecturer during the progress of the lecture. This feedback of the students stresses the necessity for precise technical implementation according to learning criteria.
6.
CONCLUSIONS
In this paper, we have presented the Virtual MultiBoard (VMB) software. Inspired by the classical multiple sliding blackboards, the software supports the display of a configurable number of pages simultaneously. The VMB currently works best with PowerPoint, as slide changes are automatically detected using a plug-in. However, any other software or hand-written pages can be used. In these cases, the educator only has to manually advance the display by selecting the “next page” button to update the display. Our evaluations so far have reflected an increased interest in VMB usage from the students. More than one student provided a free-text comment that the VMB should also be used in other classes. Criticism mostly centered on the arrangement of the auxiliary video projectors in the “mobile” setting. However, due to space and room layout constraints, we could not improve this. In the future, we plan to further consolidate the VMB GUI. After translating the screen messages into English, we will be able to offer it for interested parties.
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