iScale: Studying Long-Term Experiences through Memory - Modeling Users' Experiences with Interactive Systems - page 85

Flanagan, 1954), ask participants to report critical incidents over periods of weeks,
months or the complete time-span of the use of a product or service. In a survey
study, Fenko et al. (2009) asked participants to recall their single most pleasant and
unpleasant experience with different types of products and to assess the most impor-
tant sensory modality (i.e. vision, audition, touch, smell and taste) at different points
in time (i.e. when choosing the product in the shop, during the first week, after the
first month, and after the first year of usage). Von Wilamowitz-Moellendorff et al.
(2006; 2007) proposed a structured interview technique called CORPUS (Change
Oriented analysis of the Relation between Product and User) for the retrospective
assessment of the dynamics in users' perceptions of different facets of perceived
product quality. CORPUS starts by asking participants to assess the currently per-
ceived quality of “their” product on a number of defined facets (usability, utility,
beauty, stimulation, identification, and global evaluation). Subsequently, they are
asked to “go back in time” and to compare their current perception and evalua-
tion of the product to the moment right after purchasing the product. If change has
occurred, participants are further prompted to indicate the direction and shape of
change (e.g., accelerated improvement, steady deterioration). Finally, participants
are asked to elaborate the reasons that induced the changes in the form of short nar-
ratives, so-called “change incidents”. The obtained data can be used quantitatively
by constructing graphs of change (see Figure 5.1 for an example) and qualitatively
by exploring the reasons people give for changes.
Fig. 5.1 Exemplary dynamics of different perceived quality dimension of mobile phones.
Start and end point of each dimension are based on the mean elicited ratings of eight partici-
pants. Reprinted from von Wilamowitz Moellendorff et al. (2006)
A common critique of methods relying on memory is the degree to which recalled
experiences are biased or incomplete. In the context of perceived product quality, we
argue that this is of minor importance. While a given reconstruction from memory
should be truthful (i.e., reflect what the participant really thinks), it seems less im-
portant, whether the reconstructed timeline as well as the reasons given are true (i.e.
reflect what actually happened) as long as the participant is convinced that what she