iScale: Studying Long-Term Experiences through Memory - Modeling Users' Experiences with Interactive Systems - page 108

actions, whereas stimulation cannot be allocated to specific events. Thus, the effect
of chronological order in reconstruction may be more salient in the case of contex-
tually rich experiences than in case of more abstract ones.
Finally, contrary to our expectations, the constructive iScale resulted in higher
test-retest consistency of the participants' graphs (i.e. value-charged information)
than the value-account iScale. We expected that the value-account iScale would re-
sult in a higher consistency in the graphs, because this information is assumed to
be cued directly from a hypothetical memory structure (Betsch et al., 2001). In con-
trast, for the constructive iScale, we assumed that this information is reconstructed
from contextual details recalled from episodic memory. This would quite naturally
result in lower consistency across repeated recalls, as long as the repeated chrono-
logical reconstruction is likely to cue different sets of experiences, which in turn
leads to a different reconstructed shape of value-charged information over time. Our
expectations were not confirmed as graphs elicited through the constructive iScale
were more consistent than ones elicited through value-account iScale with a moder-
ate to large effect size (d=0.8). This might relate to the finding of Reyna and Kiernan
(1994) that participants may falsely recognize the overall gist of a memory, while
correctly recalling its exact details.

5.5 Conclusion and Future Work

This chapter has presented iScale, a graphing tool to elicit change in product per-
ception and evaluation over time. It took the general approach of retrospective re-
construction of users' experiences as an alternative to longitudinal studies. More
specifically, the tool was designed with the aim of increasing participants' effective-
ness in recalling their experiences with a product.
We created two different, theoretically grounded versions of iScale. The con-
structive iScale tool imposes a chronological order onto the reconstruction of expe-
riences. This will increase the contextual cues surrounding the experienced events,
cues used to reconstruct value-charged information (i.e., affect). The value-account
iScale aims at distinguishing the elicitation of the two types of information: the
value-charged and contextual cues. It assumes that value-charged information can
be recalled from a separate, specific memory structure.
Study 1 provided qualitative insights into the use of iScale and compared it to
free-hand graphing. The study highlighted the importance of annotations and led to
a redesign of iScale with two new forms of annotation, (a) timeline annotation that
allowed users to set the start and end date of graphed segments, and (b) a visual-
ization of experiences on the main, graphing, interface that allowed an overview of
one's storyline. Overall, the study confirmed our expectations that free-hand graph-
ing is more expressive than iScale due to the increased degrees of freedom in graph-
ing as well as due to its ability to easily annotate graphs. Nevertheless, participants
reported qualities present in iScale, such as two-step interactivity and modifiability
of the electronic graphs, which resulted in a better interoperability of graphing and
the recalling activity.