iScale: Studying Long-Term Experiences through Memory - Modeling Users' Experiences with Interactive Systems - page 93

They were: five Computer Scientists, three Industrial Engineers, two Linguists, one
Psychologist and one Industrial Designer.

5.3.1.2 Procedure

The study consisted of two parts. In the first part, each participant used three differ-
ent graphing techniques: free-hand graphing (FHG) and the two iScale tools (con-
structive & value-account). All tasks were carried out on a Wacom Cintiq 21UX
Interactive Pen Display. The order in which the tools were employed was counter-
balanced across participants; FHG was always used first to avoid any bias from the
iScale tools as we wished to understand users' natural behavior in graphing changes
in perception, evaluation and feelings over time.
Participants were asked to graph how their opinion on three distinct qualities of
their mobile phone changed over time (see table 5.1). Each quality was described
by a brief definition and three attributes to support the definition (Hassenzahl, 2004;
von Wilamowitz Moellendorff et al., 2006). Qualities along with their definitions
were derived from von Wilamowitz Moellendorff et al. (2006), though we rephrased
the construct names utility and stimulation to usefulness and innovativeness as the
former were not clear to some participants in our pilot tests. These qualities are
routed in Hassenzahl's (2004) model that distinguishes pragmatic quality ,which
refers to the product's ability to support the achievement of do-goals such as mak-
ing a telephone call, from hedonic quality , which refers to the product's ability to
support the achievement of be-goals such as being stimulated or being admired.
Participants were instructed to think aloud; interactions and verbal data were cap-
tured on video. Each graphing task took approximately four minutes (min=81 sec,
max=594 sec). No significant differences were found between the three tools (con-
structive: M=230 sec, SD=147 sec; value-account: M=205 sec, SD=87 sec; free-
hand graphing: M=301 sec, SD=130 sec).

“While graphing, you are asked to report experiences and events that in-
duced these changes in your view of the product. We are interested in your
exact thoughts and feelings as you perform the graphing. Why do you graph
it in this particular way? What details of events, incidents, experiences do
you remember? Is it just a feeling? Please think aloud while doing this.”

Ta b l e 5 . 1 The three aspects, their definition and attributes.

Name Definition Word items

Usefulness The ability of a product to provide the

necessary functions for given tasks.

Useful, Practical, Meaningful

Ease-of-use The ability of a product to provide the

functions in an easy and efficient way.

Easy to use, Simple, Clear

Innovativeness The ability of a product to excite the

user through its novelty.

Innovative, Exciting, Creative