think-cell technical report TC2003/01 A GUI-based Interaction ...

6.2 Case Study EVALUATION
presented that suggests that the concepts of this work support the speed-up goals
of the over-all application.
6.2.1 Question
The ultimate goal of the application is a speedup-factor of about 5 in the PowerPoint-
related workflow of a business consultancy. While using plain PowerPoint, the ne-
cessity to rearrange elements when text comes into play becomes the major time
consumer. Depending on the quantity of text that the different shapes contain, the
slide is iteratively refined until all text is readably sized and nicely wrapped, all
elements are aligned and have uniformly distributed space between them, and so
forth. An increase of efficiency is expected to result from the solver that updates
and maintains relations between elements on the slide whenever the user makes
some arbitrary addition or modification. With this approach, all the time that is
currently spent in iteratively rearranging the slide layout, would be eliminated.
In this scenario, it is important that the user interaction required to specify
layout constraints does not require any more effort or time than the user interaction
that is currently required to create a pixel-based layout in PowerPoint. It is therefore
the job of the user interface and the goal of my thesis to facilitate the constraint-
based specification of a certain layout in the same or less time than it takes to
specify the same layout using plain PowerPoint.
6.2.2 Setup
To validate the concepts implemented in my prototype, I chose a representative
sample of 20 slides from a number of original business presentations. The case study
was designed to compare two conditions: The user interface of plain PowerPoint
vs. the user interface presented in this work. For each condition, I had an expert
copy the layout of those 20 slides from a printout to a PowerPoint slide or smart
grid, respectively. In order to measure the impact of the user interface for layout
specification as precisely as possible, no text or formatting was applied to the slides.
That way, the influence of automatic text wrapping and constraint-maintaining
layout was excluded from the measurement and the times taken are exclusively due
to user interaction that specifies alignment of shapes.
To measure time for the plain PowerPoint interface, I hired a professional from
a business consultancy’s visual pool, who was rated by his superior as one of the
fastest PowerPoint users in the team. As the only available expert for the new smart
grid user interface, the author did the timing by himself. Both experts created the
20 slides in the same order and in one batch.
6.2.3 Results
Figure 48 lists the results from the competition. For 3
4 of all slides as well as on the
average, the smart grid interaction concept was faster to use than the traditional
PowerPoint UI. In 3 cases the speedup difference was greater than 60 %. Based on
85