MultiPresenter:
A Presentation System for (Very) Large Display Spaces
Joel Lanir
Kellogg S. Booth
Anthony Tang
Dept. of Computer Science
University of British Columbia
Vancouver, BC, Canada
Dept. of Computer Science
University of British Columbia
Vancouver, BC, Canada
HCT Lab
University of British Columbia
Vancouver, BC, Canada
yoel@cs.ubc.ca
ksbooth@cs.ubc.ca
tonyt@ece.ubc.ca
ABSTRACT
We introduce MultiPresenter, a novel presentation system
designed to work on very large display spaces (multiple displays
or physically large high-resolution displays). MultiPresenter
allows presenters to organize and present pre-made and dynamic
presentations that take advantage of a very large display space
accessed from a personal laptop. Presenters can use the extra
space to provide long-term persistency of information to the
audience. Our design deliberately separates content generation
(authoring) from the presentation of content. We focus on
supporting presentation flow and a variety of presentation styles,
ranging from automated, scripted sequences of pre-made slides to
highly dynamic ad-hoc, and non-linear content. By providing
smooth transition between these styles, presenters can easily alter
the flow of content during a presentation to adapt to an audience
or to change emphasis in response to emerging interests. We
describe our goals, rationale and the design process, providing a
detailed description of the current version of the system, and
discuss our experience using it throughout a one-semester first
year computer science course.
Categories and Subject Descriptors
H.1.2 [User/Machine Systems]: Human factors, Human
information processing; H.5.2 [User Interfaces]: Graphical user
interfaces (GUI), Interaction styles (e.g., commands, menus,
forms, direct manipulation), User-centered design; H 5.m [User
Interfaces]: Information interfaces and presentation (e.g., HCI):
Miscellaneous.
General Terms
Design, Human Factors.
Keywords
High-resolution displays, Human-Centered Design, Multiple
displays, Presentations.
Permission to make digital or hard copies of all or part of this work for
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requires prior specific permission and/or a fee.
MM ‟08, October 27 – November 1, 2008, Vancouver, BC, Canada.
Copyright 2008 ACM 1-58113-000-0/00/0004…$5.00.
Figure 1: The MultiPresenter system in use.
1. INTRODUCTION
Electronic slide presentations are multimedia events that integrate
visuals such as images, video, animations and text with the spoken
words of the presenter. ―Slideware‖ tools, the generic name for
software such as PowerPoint that support these presentations, are
enormously popular and are the predominant visual aid in
business, conference and other types of presentations. Microsoft
estimated in 2004 that about 1.25 million PowerPoint
presentations were given every hour [18]. Slideware has become
ingrained in presentation culture: a New Yorker article in 2001
suggested that to ―appear at a meeting without PowerPoint would be
unwelcome and vaguely pretentious, like wearing no shoes‖ [25].
Yet, many authors have suggested that slideware imposes a
singular, sequential, frame-by-frame presentation style that best
suits static and linear content [14, 16, 33]. Recent studies have
demonstrated that academic instructors using traditional
presentation technologies, such as blackboards or whiteboards,
are able to more easily employ a far greater range of presentation
techniques, such as referring to previously presented content,
providing visual comparison between different concepts, and
moving through presentation content non-linearly [16]. These
presenters frequently make use of the larger space available with
whiteboards, purposefully using some areas for content that will
be referred to later, and using other parts to support ad-hoc or
spontaneous presentation material. The problem we see is that
slideware systems support dynamic multimedia content, but they
do not as easily support dynamic presentations; they are primarily
designed for preparing fixed, sequential presentations of slides.
We then show how features of MultiPresenter provide additional
control of visual aids to presenters, realizing this design approach.
Finally, we discuss the experiences of a university instructor who
deployed the system in a real classroom setting for one semester.
2. PREVIOUS WORK
Figure 2: Many lecture halls and conference rooms have
multiple screens.
Our interest is motivated by the growing availability of very large
electronic display spaces, especially in classrooms, and the
limitations we have experienced giving slide presentations on a
single, normal size display. No doubt as a consequence of the
ubiquitous use of slideware, lecture halls are increasingly being
built with advanced technological infrastructure to support
electronic presentations.
Because many universities and
conference centres accommodate hundreds of audience members,
lecture halls and conference rooms are now frequently equipped
with multiple, high resolution display systems (Figure 2). This
infrastructure can, in theory, provide instructors with the same
amount of screen real-estate as do lecture halls that employ
whiteboards. Most slideware does not yet take advantage of this
extra screen real-estate; in fact, many lecture halls simply default
to broadcasting the same slideshow on all of the displays.
We examined questions that address both pedagogical and
pragmatic concerns: How can we build presentation tools to best
support learning and retention of presented information? Further,
how can these tools best employ the additional screen real-estate
provided by modern lecture halls?
To test our ideas, we developed MultiPresenter, a prototype
multiple-display presentation system (Figure 1). MultiPresenter
realizes a design approach and philosophy that separates the
creation of content from the presentation of content. It offers two
key advantages over traditional approaches.
Most slideware tools are presentation content authoring
systems, and in many ways do not fully support the dynamic
nature of presentations. In contrast, MultiPresenter was
developed focusing on the actual practice of presentation. It
supports many common presentation practices other than just
sequential slides. It allows presenters to change the flow of a
presentation, place persistent content on auxiliary screens for
later reference, and interactively manipulate content and
information during presentations.
MultiPresenter supports fully scripted, semi-automated, and
manual control of multiple screens. This provides presenters
with more control over how visual aids are used during a
presentation. For example, a presenter may show two slides
simultaneously for comparison, or to have an important slide
visibly persistent for a longer period of time, or to construct
meta-slides based on content from other slides.
In this paper, we describe how prior work motivated our work
with presentation systems, articulating how findings from studies
exploring actual presentation practice suggested the need to
support more dynamic presentation practices. We then articulate
how separating content and presentation authoring gives
presenters more conceptual control over the presentation material.
There is a long history and a large literature on document
preparation systems, of which slideware is just a subset, and
dynamic visualization techniques ranging from animation systems
to add-ons for common GUI interfaces. We focus on the
shortcomings of existing slideware tools and recent attempts to
return to more ―natural‖ interaction styles that mimic traditional
blackboard and whiteboard techniques.
2.1 The PowerPoint Debate
The most prominent presentation tool is PowerPoint, which in
2001 was said to control about 95% of presentations world-wide
[25]. Consequently, PowerPoint has generated much criticism,
but similar complaints can be applied to most presentation tools,
including Apple‘s Keynote or OpenOffice‘s Impress. For clarity,
we will use the terms slideware and PowerPoint interchangeably
to refer to this class of tools.
The best-known critic is former Yale professor and information
visualization expert Edward Tufte. In his essay ―The Cognitive
style of PowerPoint‖ [33] he claims that PowerPoint is presenteroriented and not content-oriented or audience oriented.
According to Tufte, PowerPoint has low resolution of data,
degrades communication by forcing users to separate content and
analysis, reduces concepts to bullets, and enforces strict
hierarchies that are not needed. More relevant to our purposes,
one of Tufte‘s major claims (echoed by others) is that PowerPoint
breaks up the narrative and data into small fragments [14, 25, 33]
by supporting a rapid temporal sequence of thin information that
is not suited for learning, instead of supporting complex reasoning
and thorough analysis.
Tufte‘s criticism was the high point of a backlash against
commercial presentation tools [14, 25, 23, 31]. The debate was
not entirely one-sided. Others suggested that PowerPoint and
other commercial presentation software are only tools, which are
sometimes used poorly by its users. Rather than being the source
of poorly planned, disorganized presentations, PowerPoint simply
reflects flaws in authors‘ design skills, communication ability, or
rhetorical expertise [22, 30]. A second argument in response to
Tufte‘s and others criticism is that oral presentation is different
from written documents, so one should not analyze slides outside
the context of the talk [6]. A core drawback of this debate is that
it has been conducted primarily through essays that reflect
authors‘ opinions rather than relying on empirical study [9].
2.2 Presentation systems
Various researchers have developed presentation tools to address
some of the limitations of PowerPoint and other commercial tools.
Some focused on adding support for delivering a presentation,
using physical index cards that are digitally linked to slides [17],
or handheld devices to better control the presentation flow [21].
Others added support for a presenter‘s view which is different
than what is seen by the audience [3, 29].
Some support for more dynamic presentations focused on
changing the linear manner of transitioning between slides.
Mindmaps, special diagrams linked to and arranged radially, were
used [12] to avoid the inherent linearity of commercial
presentation tools and to provide explicit information about the
structure of a talk. Zoomable User Interfaces [11] have been used
to break the linearity of a presentation; using ZUIs, static slides
are arranged on a large canvas at various scales. Transitions are
made between slides using pan and zoom across the canvas,
allowing viewers to understand the structure of the talk according
to the visual locations and groupings of the slides. These
approaches separate content from the actual presentation by
making the navigation through the information space a core part
of the presentation delivery. Similarly, SLITHY [34] provided a
conceptual separation between content and presentation and
focused on design principles of animation for use during
presentations.
SLITHY incorporated animations into
presentations by providing authors with a scripting language that
operates the animation using a content layer. We build on this
core approach of separating content from presentation delivery,
and provide presenters with presentation mechanisms that
facilitate persistence of content during a presentation.
Many multimedia projects have focused on capturing, processing,
archiving and retrieving live presentations. Classroom 2000 [1]
was the first major project to incorporate technology in the
classroom to facilitate capturing, archiving and retrieving records
of classroom activities. Mukhopadhyay and Smith [20] aimed at
capturing lectures using a more passive and less invasive
capturing process. Others emphasize integrating the various
captured streams (audio, video, slides, and whiteboard) for later
retrieving in various levels of automated methods [13].
Some projects deployed presentation technology in classrooms
with the goal of enhancing learning. Approaches enhancing faceto-face communication in the classroom aim to make
presentations more dynamic by adding electronic ink to the
presentation. PowerPoint 2007 has some annotation tools to
support electronic ink. Classroom Presenter [3] added more
complex writing tools to augment prepared slides by integrating
PowerPoint slides with pen-based writings on a tablet PC. EChalk [10] allowed instructors using electronic whiteboards to
combine the ability to record whiteboard activities with
multimedia items and pen-based writing in classrooms. All of
these systems suggest the importance of electronic ink as a tool to
add some degree of dynamic interaction for the presenter, whereas
other systems added dynamic tools such as task management,
polls or newsgroups to presentations systems in order to enhance
participation of students in classrooms, utilizing workstations or
mobile devices used by students [8, 26, 27].
There has been some effort to support delivering presentations on
multiple projectors. Röüling et al. [29] implemented a system that
showed previous slides on different projectors. They also
supported electronic ink and a separate view for the instructor.
Chiu et al. [5] also proposed a slide-based multi-display
presentation system. In their system, the presenter was able to
show previous slides on multiple displays, and was able to use a
touch interface to control the flow of slide presentation. We use
these systems as starting points, supporting multiple projectors for
slides and providing support for existing slideware tools. We
augmented this with support for dynamic presentation practices
and some new static practices, and we simplified the infrastructure
requirements to allow more rapid adoption.
3. PRESENTATION PRACTICES
In previous work [16], we briefly introduced MulitPresenter
which was then in its early design stages. Our previous study was
an observational study to understand how presenters employ
visual aids such as blackboards, whiteboards and slides to inform
the design of MultiPresenter. In this paper, we expand on those
ideas, fully describing MultiPresenter‘s feature set, and on our
goals, rationale and design process. Further, we discuss an initial
evaluation of the system. To set the scene for MultiPresenter‘s
feature set, we rearticulate some of the findings from prior work
[16] that identified presentation practices common with traditional
technologies, but are inadequately supported with current
slideware tools.
Spontaneous and non-linear presentation styles. In contrast to
slideware presentations, presentations using traditional
technologies were frequently spontaneous, dynamic and often
non-linear. Presenters frequently diverged from what appeared to
be a planned path through the content, to drilling down into
content when necessary, or spontaneously using visual aids either
to answer questions or to follow important tangents or facilitate
discussions when appropriate.
Revisiting earlier information.
With traditional media,
presenters many times referred back to previously written
content—sometimes to information recently presented, and other
times to content originating from much earlier in a presentation.
This practice was employed differently for more recent content
compared to older content, but in both cases there was convergent
evidence of the non-linear presentation styles in what we
observed. Revisiting illustrates the importance of persistent
content on the display—it is only because information is
persistent in traditional media (especially blackboards and
whiteboards) that referring back to content is possible.
Creative use of multiple sliding whiteboards. Many lecture
halls we observed had as many as nine sliding whiteboards in a
33 grid of boards, and frequently instructors made use of all of
them. Sliding boards afford an extremely large surface, allowing
an entire lecture to be visible to the audience, and, while it is a
large space, the seams between the whiteboards facilitate a form
of partitioning. We saw highly creative use of these partitioned
spaces: instructors might place important content in a top corner
to be easily referred to later as a reinforcing mechanism; in other
instances instructors wrote a problem on one board, a diagram
explaining the solution on a different board, and the formal
solution on yet another board.
During their explanation,
instructors might switch back and forth adding additional
information when referring to these three board areas.
Cognitive benefits of a larger space. In interviews we
conducted, instructors suggested that they needed more space to
present complex ideas, because with sufficient space, spatial
relationships between concepts could be used to encode meaning.
Indeed, studies by cognitive scientists have borne out this
sentiment: spatial and temporal grouping of related items is
important for learning [19]. When entities needed to be
compared, instructors could draw them on adjacent whiteboards,
allowing students to see both the construction of each entity, and
to see them simultaneously for comparison purposes. Slides do
not facilitate this practice so easily. As one instructor noted: “I
often feel a slide is too small, and a lot of times it‟s because there
is something I‟d put on one slide that I wish I could put on the
other slide and see them at the same time.”
Presentation as dialogue. Many presentations cannot be simply
conceptualized as one-way monologues from the lecturer to the
audience [32]. In many cases, lectures should be viewed as
dialogues, where the instructor implicitly and explicitly ascertains
whether the presentation delivery is clear in situ, and modifies
delivery technique to enforce a point by revisiting a concept, or by
providing more detail [4]. In these cases, presentation of prepared
material was highly dynamic, enabled by the dynamic nature of
the whiteboard.
Motivated by these findings, we designed MultiPresenter, a
presentation system that provides the presenter control over
multiple high resolution displays, and gives the presenter a suite
of in-presentation tools to dynamically modify the flow of a
presentation. These tools allow the presenter to make content
persistent, modify content on the fly, and re-arrange the order
slides during a presentation, independent of any originally
authored flow and of the type of the authored content.
4. SEPERATION OF CONTENT AND
PRESENTATION STYLE
Most slideware tools, such as PowerPoint, act more as content
authoring tools than presentation tools. They facilitate content
creation from a variety of media sources and provide highly
sophisticated layout schemes. Indeed, the content created often
has a life of its own outside of the context of the presentation,
being used for other purposes such as exchanging information,
official documents, students‘ notes or even entirely nonpresentation purposes, like for greeting cards or posters. As
presentation tools, they impose a fairly sequential presentation
style. They are well suited to highly structured presentations that
have a well-planned and singular flow. Yet we have seen that
presenters often employ a variety of presentation practices beyond
this structured sequential flow when given the presentation
medium (boards) that affords this. Our core design approach was
therefore to separate content from presentation, and in so doing,
build a presentation system whose sole focus is providing
presenters with in-presentation tools to support dynamic
restructuring of content as well as to support various static
practices. In this section, we articulate the philosophy behind this
design approach.
We distinguish between the content, the layout, and the
presentation of a presentation (Figure 3). The content of a
presentation may include text, images, videos, clip art or other
types of media. The organization of this content onto slides is the
layout. The presentation layer consists of the animations within
slides, animations between slides, and the transitions from one
slide to another (i.e. – the order of slides presented). These three
layers are logically distinct. In fact, they could be constructed by
three different people. For example, a CEO of a company might
have her assistant develop the content, a graphical designer
formulate the layout of that content using PowerPoint slides, and
then deliver the presentation herself using her unique personal
presentation style.
With most conventional slideware tools, such as PowerPoint, all
three aspects of a presentation are constructed simultaneously,
thereby marrying content and layout alongside presentation
semantics. The key drawback of this approach is that layout and
Figure 3 –Separating Content, Layout and Presentation style
presentation are unified instead of allowing flexibility during
presentation delivery. Some presentations need to be more
dynamic: instructors with traditional presentation technologies
often reframe or spontaneously provide more detail about
concepts if they see that students do not understand the content
[4]. Thus, presentations are often dynamic events in which a
fixed flow of slides (during authorship) does not meet the needs of
either the instructor or the audience.
MultiPresenter focuses on the presentation layer of this process,
independent of the content authoring and layout processes. It
provides the presenter with different ways and styles to give a
presentation, facilitating fully automated scripted transitions
between slides, completely ad-hoc use of content, and hybrids that
semi-automate presentation while still allowing spontaneity.
MultiPresenter provides smooth transitions between these
presentation styles even during a presentation. Thus, presenters
can construct the flow, or ―presentation layer‖ of a presentation
independently (i.e. after) authoring the content and layout of the
slides themselves, right up to and during the actual presentation of
the material.
By separating the presentation layer from the layout and content,
we facilitate more dynamic presentations because the flow of the
presentation can be specified during a presentation, rather than
during the authoring process. A presenter is able to choose before
or during the presentation the specific content or layouts (slides)
that he or she wants to be seen at a given time. This separation
facilitates many different types of presentations other than the
one-slide-on-one-screen commonly used by PowerPoint and other
slideware tools. This can be seen in the upper part of Figure 3,
which illustrates the presentation layer.
Beyond simply
supporting modification of the flow of the presentation,
MultiPresenter also provides several tools that allow the presenter
to change the way content is presented. We discuss these tools
further in the next section. They allow content to be shown
differently than in typical slideware. A presenter may choose to
only show slides on one projector, while using the second
projector as a scratch space. Alternatively, slides or specific
content can be selected for persistence and be displayed on the
second projector for an extended period of time, allowing the
presenter to refer back to that information.
Separating
presentation from content is a powerful enabling design concept
that MultiPresenter uses in many ways.
Electronic ink is really another concept altogether, because it is
related to the presentation, the layout and the content. Electronic
ink is written during the presentation, and can be used for
attentional gestures – to emphasize or show certain areas in a
diagram on the slide [2]. It is therefore part of the presentation
layer. Yet, it can also be part of slide layout, if the presenter uses
ink to connect two objects on the slide, or as basic content if a
presenter uses it to write persistent information. Ink should thus
be considered as a separate layer, because in certain instances,
such as when reusing the slides for a new presentation or when we
are only looking at the presentation slides without the talk, we
want to separate out or even completely disregard the ink layer.
Separating content and presentation has significant implications
for archiving. Current slideware only provides limited support for
creating several different presentations from the same content. By
explicitly separating content creation from presentation
authorship, multiple presentations can be created and stored
referring to the same source content. Most slideware typically
assumes that a stored presentation is a file containing the content
and layout; however, if we wish to save the presentation level, we
should also consider the dynamic presentation delivery as a core
part of the presentation, so we must archive it for future viewing.
Unlike content and layout, the presentation level is dependent on
time. We must archive the events as time related – which content
appeared where and at what time.
Separating content and presentation is a common design
philosophy. We have seen the philosophy employed on the web,
where XHTML defines the semantic content and structure of
webpages, while CSS or XSL style sheets define the visual layout
or presentation of content. Similarly, LaTeX [15], Scribe [28],
and UNIX‘s troff [24] all employed this philosophy years earlier
in the typesetting domain. These systems embody the understood
advantages of separating the authoring of content from the
presentation of that same content, which allows each process to be
more flexible and independent. The same content can be easily
presented in different styles (technical report, journal article,
academic thesis) if either content or presentation can be changed
without affecting the other. For example, a link can be shown in
one style as a footnote, in another style as a reference to be written
at the end of the document, and in another style it can be treated
as a hyperlink to a web page. In MultiPresenter, we do much the
same thing by separating the authoring and layout of content,
which is done elsewhere, from the presentation of the content in
real-time, which is done using our system.
5. MULTIPRESENTER
5.1 Infrastructure Support
Our goal was to build a system that would be simple and usable.
Simplifying the infrastructure support from what was required by
prior work, which often relied on complex technical setups [5,
29], was a core design goal to enable lightweight deployment: the
system should be capable of running on a standard laptop
connecting to existing projectors in any room. We believe that
most presenters would like to retain control over their content and
Figure 4: The User-centered approach of MultiPresenter.
use either their laptops or the room‘s PC to run their
presentations. We definitely did not want to assume that major
investments in new projector infrastructure would be made.
The primary requirement for MultiPresenter is for the computer to
be able to control the entire display space. If there are two
displays, this means having two video cards to control the two
screens. Large lecture halls and conference rooms that have two
or more projectors or displays set up in the room usually are
accompanied by a dedicated computer that controls one or both of
the screens. To accommodate the control of two screens by the
room computer all that is needed is add another graphic card to
that computer (if it does not already exist) and enable connection
of the computer to the two screens via the control system of the
room. This is a simple task that can be done in any room with
existing infrastructure that controls two screens.
In order to run our system from a laptop, we need the laptop to
have two or more graphic cards to be able to control multiple
screens. In order to add another graphic card, it is possible today
to use various solutions. The VTBook™ connects to the
PCMCIA slot of a laptop and adds a graphic card that can connect
to a DVI or VGA port.
Matrox‘s DualHead2Go™ or
TripleHead2GO™ are devices connected on one side to the
laptop‘s VGA output and on the other side to two or three screens
or projectors; allowing the laptop multi-display capability by
simulating one large surface spanning all screens of up to
3840X1024 pixels. The simplest and cheapest solution that exists
today (less than 100$) is to use a USB to VGA adaptor that adds
another graphic card to the laptop with a simple plug-and-play
USB interface.
As the resolution of graphics cards increase, it is possible for a
single computer to control a large volume of pixels. With the
advancement of networked projectors, and the increased
resolution of projectors, future laptops will be able to control
more projected pixels either on one or multiple screens. The real
challenge is not the technical question of how the infrastructure
will be built, but rather how we can design tools that make use of
this abundance of display space to create better presentations.
5.2 Design Process
In designing MultiPresenter, we took a User-Centered Design
approach (Figure 4). Most systems have one type of user that the
designer has to focus on when designing the system. In our case,
users are both the presenters and the audience.
Figure 5 – Authoring view showing the visual presentation of
the presentation across multiple projectors
First focusing on the presenter, we emphasized usability of the
system. It was imperative that the system would be easy and
intuitive to use – especially during a presentation when the
presenter needs to pay attention to the material and often cannot
afford to devote much cognitive effort to running the presentation.
To better understand this and other requirements, we involved
instructors and presenters early in our design process. Presenters
were shown the interfaces of early prototypes and were
encouraged to comment and to suggest needed features. We then
iterated on the prototypes, changing the design and solving
problems during each iteration.
We next focused on the audience, trying to understand how to
build presentation software that would promote the audience‘s
learning or understanding of the material. Using extra screen
space in a presentation does not necessarily help the observer.
Showing too much information that is redundant to the spoken
words may in fact hinder the learning process [19]. Although,
this is very dependent on the way the presenter uses the system,
we tried to build the system in a way that the presenter would be
guided to use it according to what we found would best aid
audiences‘ learning [16].
5.3 Design Goals
During the design process of the system, we had several goals
stemming both from our previous research and from the design
process:
Separation of content and presentation – As stated earlier,
we wanted users to understand that the system was a
presentation system, different from their existing slideware
authoring tools. Presenters should understand implicitly that
the system focused primarily on enhancing the presentation
process. Thus, MultiPresenter does not support authoring of
slide content. PowerPoint and other slideware tools already
do a very good job building slides using different fonts,
backgrounds, diagrams, clip art and other media. So content
can be created with existing authoring tools and then be
imported into MultiPresenter as a set of images. A
PowerPoint plug-in to directly import content and run a
presentation is possible, but not yet implemented.
Figure 6 –Presentation view of the material shown in Figure 4
Support both dynamic and non-dynamic modes – We wanted
to support different types of presentation styles, most notably
both dynamic and static styles of presentations. Static,
scripted presentations are better for reducing cognitive load
on the presenter because the presenter only needs to advance
the pre-made materials. Dynamic presentations are important
when some ad-hoc or spontaneous interaction with the
audience are needed.
Usable in practice – We wanted the system to be as usable as
possible in the real world. We therefore designed the system
to run from one computer. For the system to be adopted, we
believe it must support compatibility with existing practices
of current presentation software. Presenters already are used
to running slide decks in a sequential matter. If we want
people to use the system, we need to use this as a starting
point, building upon users existing way of presenting slides
while adding other features that afford other possibilities.
Reuse of content – Presenters already have existing singledisplay slide decks. Some have invested significant effort in
preparing this material. Presenters should be able to use
previously authored content and existing presentations in the
context of multiple screens with minimal effort.
Minimize cognitive load – When giving a presentation, the
presenter needs to focus on delivering the presentation itself,
rather than on the interface to the presentation software. The
use of the presentation system must be intuitive and must
demand minimal cognitive resources from the presenter.
5.4 System Description
MultiPresenter comprises two pieces: presentation authoring and
presentation delivery modes. The presentation authoring mode
facilitates the creation of the flow of the slides, and is used before
delivery of the presentation. The presentation delivery mode is
invoked during presentation and provides the view displayed by
each projector, and allows the presenter to easily switch between
scripted flow, ad-hoc flow, or completely manual control of each
projector view.
Figure 7 –Showing the two previous slides provides
immediate context
5.4.1 Presentation authoring
The presentation authoring mode allows a presenter to author the
flow of a two- (or more) projector presentation from existing
slides, and should not be confused with content authoring (which
is done using an external slideware tool such as PowerPoint). In
the authoring view (Figure 5), the presenter can design a pre-made
presentation for two screens. There are two columns of slots into
which slides can fit, representing the two screens. An existing
slide deck presentation loads into a single column. The user can
author a dual-screen presentation using simple and intuitive direct
manipulations tools such as copying, moving or stretching any
slide to one or more locations in the second column. For
example, the presenter can drag an overview slide to the second
display and mark it so it will be seen during a predefined part of
the presentation. When running the presentation, the slides will
show as the presenter sees it in the two columns.
Using the authoring view, a presenter can build a pre-made
presentation that will show slides on either of the two screens or
on both simultaneously. This is useful when comparing two
slides (e.g. an art history presentation comparing two paintings),
when showing an overview slide and a detail slide (i.e. having an
overview of the presentation with the current location always
visible), or when keeping an important slide visible for part of the
presentation alongside the regular stream of slides (i.e. a
chemistry lecture showing the periodic table throughout the
lecture). Any pre-made presentation that has been authored can
be saved to be reloaded at a future time.
The basic authoring view supports building a scripted
presentation that assumes the presenter does not wish to interact
with the system during the presentation. Many presentations, like
sales pitches or conference talks, are prepared talks in which the
presenter has prepared the entire sequence of slides in advance.
In these types of talks, there is usually no need for the presenter to
interact with the system other than progressing to the next slide.
Similar to PowerPoint, the presenter decides beforehand exactly
what will be seen on the screen (in this case on both screens), and
progresses forward in time in a linear fashion.
Our presentation authoring mode also affords creating multiple
―presentations‖ from a single set of slides, each of which can be
saved, loaded and employed separately without modification to
Figure 8 – Dynamically clipping content to the secondary
screen
the content.
While some existing slideware tools (e.g.
PowerPoint) can be used in this way, the functionality is not
readily exposed by the interface, and is frequently somewhat
difficult to use. Typically, users create multiple versions of the
same slide deck, and cut-and-paste slides—a non-optimal solution
since content changes are not propagated across slide decks.
Drucker et al. [7] explored ways to compare and manage multiple
slide presentations, but their focus was on managing multiple
presentation versions and not on the presentation act itself. This
particular example highlights the strengths of the design
philosophy of separating content from presentation.
5.4.2 Presentation delivery
Figure 6 shows the presentation delivery view (that the presenter
sees). This view shows the current two slides on display, and
enables the presenter to navigate to different areas in the
presentation. The presentation delivery view gives the presenter a
powerful set of tools that facilitate many of the presentation
practices common to traditional presentations. The view also
gives presenters the ability to dynamically manipulate the
presentation of the content during the actual presentation.
Figure 7 illustrates how the first projector can be used to show the
regular slide deck while the second projector can be used to show
one, two or four previous slides. As the presenter moves through
the slide deck, the second projector is automatically updated,
giving the audience automatic context for the current slide. The
audience is kept aware of the order of the previous slides using
animations that transition each slide to the new location on screen.
This simple configuration allows presenters to use their existing
slide decks and without any extra effort to use the second screen,
giving their audience some context for what has been previously
shown. Much of the information needed to be referred to during a
presentation is recently shown information [16], so showing the
previous four slides can give the audience the necessary context
needed to understand the current slide and can also allow the
audience to look at previous content they might have missed.
Figure 8 shows how MultiPresenter gives presenters dynamic,
interactive control of displayed content. First, the presenter can at
any time decide to select and display any slide on the second
projector, and this can stay on the display as long as the presenter
likes. This affords using the second projector as the ―reinforcing
Figure 3 –Separating Content, Layout and Presentation style
some information may be referred to again later. Using this
mechanism, the presenter can ensure that the content is easily
referred to without needing to flip back through the slide deck.
The presenter might also want to keep certain data visible together
to explain difficult concepts. In this mode, the presenter can
gather the important concepts from the stream of slides and put
them on the secondary display, thereby providing the audience
with a visual connection between concepts. In classrooms,
instructors usually prefer to have some level of dynamics to be
able to perform ad-hoc explanations and to use the visual aid to
answer questions [16]. In this mode, the instructor is effectively
given full control of how to use the second display.
Electronic ink adds another level of dynamics and allows the
audience to follow a presenters‘ train of thought. Presenters who
use tablet PCs can use a stylus in their presentations to add
annotations to existing slides. Ink can be used by showing slides
on one screen, and using the second screen as a drawing screen
for ink alone. Electronic ink can also be used to gesture and
emphasize important areas on a slide. Our system fully supports
electronic ink in different colors and sizes. The presenter can add
ink annotations to existing slides in the presenter‘s view, while
the audience immediately sees the ink annotations. Erasing ink is
also supported, as well as persistence of ink through time when
the presenter moves back and forth in the slide deck.
6. INITIAL DEPLOYMENT
To provide an early understanding of whether our design goals for
MultiPresenter were actually useful, we recruited a university
instructor to use the system to teach one of his courses. The
instructor is technically very savvy, and has a keen interest in
using and evaluating new technologies for teaching. He was also
involved in the earlier design phase for MultiPresenter, so was
already well-versed in the system‘s feature set.
Figure 9 – Dynamic mode example. During presentation, the
presenter drags content from the prepared slides on the left
screen to the scratch screen on the right allowing long-term
persistency of important content.
concept‖ that the presenter can return to throughout the entire
presentation. Second, the second projector can be used as a
―clipboard‖ of highly referred to content items that the presenter
deems important to keep persistent. To modify this clipboard, the
presenter can, at anytime, select a part of an existing slide (e.g., an
important diagram or bullet point), the entire slide, or any number
of slides. Each added slide is automatically laid out in size and
location according to the number of existing snippets. The
presenter can then move, resize or erase any snippet on the
secondary screen. All interactions are shown on the presenter‘s
laptop as well as the audience to keep the audience aware of the
origin of the information. Figure 9 shows an example of how a
presenter would use this dynamic control during the presentation
in order to keep some important information available longer.
This level of dynamics is useful, and allows the presenter to keep
certain important items visually available for longer times. For
instance, the presenter might realize during the presentation that
Figure 1 shows the instructor using the system in his classroom.
The instructor used the system for most classes of his first year
undergraduate basic computer science course (88 enrolled
students). We observed the instructor using the system, recorded
logs of the system in use (logging the events and types of usage),
interviewed the instructor during and after the semester, and
administered questionnaires to the students to assess their
subjective perceptions of the system.
The instructor used the presentation delivery system almost
exclusively in a fully dynamic mode, retaining full control over
what was being displayed on both screens at all times. He used an
existing slide deck from a previously taught version of the course
that he updated each semester. He showed this slide deck on one
screen using MultiPresenter and dragged slides to be shown on
the secondary display during the lecture as he thought fit. He used
the second display in several ways:
Showing slides that were important to keep persistent for
longer times (i.e. – important concepts, definitions, or
concepts that would be useful later).
Showing variants of a single concept on two screens. For
example, the instructor often showed the problem slide on
one screen, and the solution slide on another.
Comparing between two items. In several instances, the
instructor used the pre-made presentation mode to compare
between two slides that showed comparable concepts.
The instructor used electronic ink extensively in the class.
Many times he used the second screen for extra writing
space, either displaying a blank screen and using it as a space
for the ink, or duplicating a slide on both sides but using
different ink annotations on each side.
When asked about the utility of the system, the instructor was
enthusiastic and commented favorably on the usefulness of the
system. He noted that although the interface was intuitive and
simple to use and did not take extra resources to operate, it took
him some time to understand how to best utilize the extra display
space. He said he wanted to use the system in his future classes.
To get subjective perceptions on the utility of the system on
students‘ learning we asked students to complete an online
questionnaire about their attitudes and thoughts on the use of the
presentation system in class. Students were given a 5-point Likert
scale to examine their opinions of several statements. Eighteen
students filled the questionnaire. Seventeen out of the 18 students
agreed or strongly agreed with the statement that having two
screens helped the instructor present the material better.
Seventeen of 18 students also agreed that they would encourage
other instructors to use the system. Some of the questions and
results are presented in Table 1. In the Likert scale 1 represented
strongly disagree, while 5 represented strongly agree.
Table 1 – Students subjective ratings of the MultiPresenter
system as they have seen used in class
Question
Avg.
SD
Seeing the two slides helped me understand
the material better than a one-slide
presentation.
3.78
0.73
Having the two screens helped the instructor
present the material better.
4.39
0.78
I would encourage other instructors to use the
two screens in a similar ways.
4.28
0.75
It was helpful for me when the instructor
showed certain slides for longer periods on the
second screen.
4.5
0.92
It was helpful to me when the instructor used
both screens to compare two slides.
4.44
0.92
The presentation system helped me learn
better.
3.78
0.87
Overall, we see that students were quite positive about the system,
thinking it helped them learn and understand the material better,
and that it helped the instructor present the material better. In an
open-ended question about the advantages of the system one
student commented on some specific benefits: “Keeping an old
slide up while talking about a new one is very useful and allows a
longer time for note taking. Comparing examples on the two
screens was also helpful.”
7. FUTURE WORK
We plan to continue to develop MultiPresenter, and further
evaluate the system to understand its viability. Planned studies
include MultiPresenter‘s use in other university courses, and in
more business oriented settings.
A tighter integration with PowerPoint and other commercial tools
will be necessary to gain wide acceptance. Adding a plug-in to
PowerPoint that enables it to run a presentation using our system
will simplify things for presenters by having the authoring and
presentation capabilities in the same platform, and will also
enable them to easily run a multi-display presentation of existing
presentations without any extra effort using standard
representation templates such as ―show the last four slides‖ or
―show topic slides‖ on a second screen. Tighter integration with
PowerPoint will enable lower level access to objects on slides,
thus enabling control of individual objects during presentation
time instead of only bitmaps, which is what is now implemented.
Other features we plan to add are support for more than two
screens (our design already supports this, but we have not yet
resolved the issue of how to design a presentation that scales
across a range of display sizes or number of projectors), adding a
variety of gesturing tools, adding a dynamic text box widget to
support text entry in dynamic mode for presenters without
electronic ink capability, and archiving of the dynamic mode
interactions for long-term persistency. The archiving of actions in
dynamic mode is part of the separation of presentation style from
the content. We plan to save objects seen on all screens, and the
interactions of a presenter with all of the objects. Electronic ink
annotations will be saved on a different layer, consistent with our
earlier comments about its role at each stage of the process.
8. CONCLUSION
We have designed, implemented and evaluated a prototype for
MultiPresenter – a presentation system that allows users to show
and author presentations on large display surfaces. In order for
the system to be usable, we enable presenters to use existing
presentations and, with simple infrastructure additions, they can
run MultiPresenter from their laptops. MultiPresenter supports
both short-term and long-term persistence of data, enabling a
presenter to keep important information visible longer, and it
supports both static and dynamic presentations.
Using
MultiPresenter, a presenter can use the multiple screens now
available in many lecture halls and conference rooms to give a
better, more interesting presentation that better promotes
audiences‘ learning. We think audience members will also benefit
by being provided with more context regarding previous
information, so they can decide how to assimilate information and
what to look at as they integrate earlier information with new
information. Seeing the previous four slides, for example, an
audience member can decide which slide to look at any given
moment. We believe the control of what to look at on the
enhanced display in any given moment being transferred from the
presenter to the audience benefits both. Our initial evaluation of
MultiPresenter in a real classroom setting has suggested a number
of other improvements, and support our hope that we will
ultimately be able to demonstrate clear pedagogical benefits.
9. ACKNOWLEDGMENTS
We thank Steve Wolfman for his help throughout this project and
his willingness to try our system in the classroom. This work has
been funded by the NSERC through a strategic research network
grant for NECTAR, the Network for Effective Collaboration
Technology through Advanced Research.
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