Assisting the older driver - SWOV

Assisting the older driver
Before (n=105) After (n=40) Difference (n=40) a
Usefulness Satisfying Usefulness Satisfying Usefulness Satisfying
Right of way 0.37 ‐0.28 0.57 0.08 0.23 0.48
young 0.41 ‐0.33 0.64 0.15 0.18 0.53
middle 0.30 ‐0.44 0.53 0.04 0.28 0.68
Old 0.46 0.06 0.58 0.08 0.16 0.05
Safe gap 0.20 ‐0.22 0.05 ‐0.29 ‐0.18 0.00
Young ‐0.17 ‐0.61 0.02 0.00 0.08 0.55
Middle 0.27 ‐0.22 ‐0.07 ‐0.48 ‐0.41 ‐0.25
Old 0.52 0.27 0.30 ‐0.23 0.02 ‐0.05
View of the intersection 0.52 ‐0.10 0.49 ‐0.10 0.08 0.15
Young 0.27 ‐0.29 0.32 ‐0.38 0.08 ‐0.03
Middle 0.47 ‐0.33 0.57 ‐0.09 0.24 0.41
Old 0.93 0.56 0.50 0.15 ‐0.26 ‐0.20
Deviating rules or situations 0.43 ‐0.13 0.61 0.28 0.18 0.38
Young 0.22 ‐0.44 0.64 0.33 0.18 0.30
Middle 0.26 ‐0.34 0.70 0.30 0.60 0.75
Old 1.05 0.66 0.40 0.20 ‐0.68 ‐0.28
a Difference scores (after ‐ before) were calculated using data of only those participants that completed all parts of
the experiment. Their before‐scores on the usefulness and satisfying subscales were more negative than those for
all participants together. Tests of differences between before‐scores of participants that only filled in the first
questionnaire (n=65) and those who filled in both (n=40) were, however, not significant.
Table 8.15. Usefulness and satisfying scores for each type of message.
Differences in user acceptance between age groups were analysed separately
for opinions beforehand and afterwards (between‐subjects). To examine
whether experience with the messages affected user acceptance, withinsubjects
analyses of variance and mixed between‐within analyses of variance
were carried out. In addition, the support system was evaluated in terms of
audibility, comprehensibility, timing, trustworthiness, and the willingness of
people to buy it, based on the answers to the other questions that were
presented to the participants (see Section 8.2.8).
8.4.1. Age differences
Between‐subjects analyses of variance showed that functional age
significantly affected the initial opinions about the support system (see Table
8.16). Before having experienced the support system, functionally old
participants were more positive than functionally younger participants about
all types of messages, except for messages regarding priority regulation. Post
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