Databases Reference
In-Depth Information
Procedure 1
Experimental procedure
1:
R
= Set of recommendations for the user.
2:
E
= Set of explanation interfaces KSE, TC, PTC.
3:
for all
randomly chosen (r, e) in
R
x
Edo
4:
Present explanation using interface e for recommendation r to the user.
5:
Ask the user to rate r and measure the time taken by the user.
6:
end for
7:
for all
recommendation r in
Rdo
8:
Show detailed information about r to the user.
9:
Ask the user to rate r again.
10:
end for
11:
Ask the user to rate the explanation interfaces.
for completing the experiment since watching the recommended movies would be too time consuming.
The users were instructed to read the detailed information about the recommended movies and were then
asked to rate the movies again (lines 7-10). According to [Bilgic and Mooney, 2005], from the point of view
of an end-user, a good explanation system can minimize the difference between ratings provided in the
lines 5 (explanation rating) and 9 (actual rating). Thus we can also measure
effectiveness/persuasiveness
by calculating the rating differences. At the end of the experiment, the users were asked to give feedback
on the different explanation interfaces (as to measure
satisfaction
with the system) by rating the system
as a whole on a 0.5 (lowest) to 5 (highest) rating scale (line 11). Again, the order was randomized to
account for biasing effects.
5.4.2 Participants of the study
We recruited 19 participants from five different countries. Most of them were students at our institution
with their age ranging from 22 to 37 (average age was 28 years). Ten participants declared high interest
in movies, whereas eight were only to a certain extent interested in movies. One person was not interested
in movies at all. Table 5.1 shows some of the demographic characteristics of the participants.
Female
4 (21.05%)
Gender
Male
15 (78.95%)
A-level
9 (47.37%)
Bachelor
1 (05.26%)
Education
Master
7 (36.84%)
PhD
2 (10.53%)
Nationality
5 countries (Germany, Turkey, Brazil, etc.)
21-25
5 (26.32%)
Age
26-30
10 (52.63%)
31-40
4 (21.05%)
High
10 (52.63%)
Interest in movies
Normal
8 (42.11%)
Low
1 (05.26%)
Table 5.1: Demographic characteristics of participants (total 19).
