Personal Attribute Judgments - Modeling Users' Experiences with Interactive Systems - page 31

Ta b l e 2 . 3 Classification of attributes elicited in the study into 16 categories and three broad
themes

Effectiveness
(32%)

Efficiency (51%) Emotional Appreciation

(17%)

1. Secure 5. Fast 12. Personal

2. Reliable 6. Error-prone 13. Modern

3. In control 7. Brainless 14. Privacy

4. Multi-user 8. Cognitive load 15. Hygienic

9. Effort in searching documents 16. Environmental friendly

10. Fast (total time)
11. Easy-to-learn

2.6.3 Charting Perceptual Maps for Homogeneous Groups of

Users

In this step, a perceptual map is created for each homogeneous group of users. First,
a configuration of the stimuli is established in a k-dimensional space where their dis-
tance represents their degree of dissimilarity. Next, attribute and preference vectors
are fitted into these spaces by performing multiple regressions between the stimulus
configuration (as independent variables) and the attribute scores (as the dependent
variables).
Figure 2.6 illustrates the perceptual maps of the five groups. All five perceptual
spaces were adequately visualized in two dimensions (

2

χ test on goodness of fit,

p 0.001). Only significant attributes were retained in the final visualization, i.e.

ones that their confidence ellipse did not include the zero point of the configuration.
Attributes are represented by the bold vectors and preferences by the light vectors.
The interpretation of the perceptual maps can be done in three steps: a) identify-
ing the similarities and dissimilarities between products, b) interpreting product dis-
similarities by employing the attribute vectors, and c) inferring the values of group
of participants by relating individual preferences with perceived attributes.

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2.6.3.1 Identifying Dissimilarities between Products

One can note that all perceptual spaces are clustered in two regions, one containing
TouchToPrint , Badge and Touch & Select and the other containing Scroll List and
Direct Print . The perception of Pin Code in comparison to the other systems is less
consistent across different perceptual spaces. It is further apparent that the configu-
ration of products within these regions differs across the perceptual spaces. Groups
1 and 4 perceive differences between Scroll List and Direct Print while Groups 2,
3 and 5 perceive these two products as relatively similar. Further, Groups 1 and 5
perceive TouchToPrint and Badge as very similar in comparison to Touch & Select