iScale: Studying Long-Term Experiences through Memory - Modeling Users' Experiences with Interactive Systems - page 100

5.2a). Annotation provided users with the ability to combine an overview of the
different periods as well as the experiences that defined these periods. Annotation
also promotes interactivity as users have a better overview of the graphed pattern
and are therefore more likely to modify it.

5.4 Study 2: Benefits and Drawbacks of the Constructive and

the Value-Account Version of iScale

While iScale appeared to be a viable alternative to free hand graphing, the com-
parative benefits and drawbacks of both iScale variants merited a second study. We
compared the constructive and the value-account version of iScale to a control con-
dition that entailed reporting one's experiences with a product without any support
through graphing. We focused on the number, the richness, and the test-retest con-
sistency of the elicited experience reports.

5.4.1 Method

5.4.1.1 Participants

Forty-eight individuals (17 Female, Median Age=23, Min=18, Max=28) partici-
pated in the experiment. They were all students at a technical university and were
rewarded for participating in the experiment; 19 of them majored in management
related disciplines, 16 in design, and 13 in natural sciences and engineering. They
all owned a mobile phone for no less than four and no more than eighteen months;
16 participants owned a smart phone. No significant differences were found be-
tween participants in the constructive and the value-account condition in length of
ownership (M con = 13 months, M va = 10 months, t(46)=1.51, p=.13) and type of
mobile phone (5 participants owned a smart phone in the constructive condition, 11
participants in the value-account,

2 =2.3, p=.13).

χ

5.4.1.2 Materials

Three different versions of iScale were used in the experiment: constructive , value-
account ,and no-graphing (control). The constructive and value-account versions
employed the two distinct graphing approaches described earlier. No-graphing was
a stripped-down version of iScale, with the graphing interface completely removed.
Thus, users were only provided with the interface to report experiences (see figure
5.3a) and this was used as a control condition to test the effect, if any, of graphing.

5.4.1.3 Study Design

A 3x2 study design was employed with mode of recall (constructive, value-account,
no graphing/control), and product quality being reported (i.e. ease-of-use versus
innovativeness) as independent factors.