1. DualDiv: Diversifying Items and Explanation Styles
in Explainable Hybrid Recommendation
Motivational examples
How to diversify explanation styles?
Experimental results
NonDiv ItemDiv RandDiv DualDiv
Recall@50 0.115 0.111
Recall@10 0.190 0.173
Recall@20 0.311 0.275
AILD@50 0.680 0.753
AILD@10 0.715 0.776
AILD@20 0.745 0.804
EILD@50 0.391 0.433 0.644 0.731
EILD@10 0.454 0.480 0.632 0.699
EILD@20 0.517 0.537 0.628 0.686
WEILD@50 0.117 0.0985 0.159 0.184
WEILD@10 0.122 0.100 0.141 0.157
WEILD@20 0.128 0.0993 0.122 0.135
 DualDiv can improve AILD without largely decreasing Recall.
 DualDiv can greedily select the three most appropriate ESs
regardless of the number of candidate ESs (cf. RandDiv).
 DualDiv can successfully select dissimilar sets of ESs,
especially between similar artists (cf. WEILD).
National Institute of Advanced Industrial Science and Technology (AIST)Kosetsu Tsukuda and Masataka Goto
Explanation: not diversified
1st
rock
The Beatles
band
Artist-based
Popularity-based
2nd
rock
Muse
band
3rd
rock
Queen
band
I want to listen to
a pop artist now.
rock band
pop 90s
pop punk
I do not think artist-based
and tag-based explanations
are persuasive.
rock band
pop 90s
pop
Avril Lavigne
punk
I think a friend-based
explanation is persuasive,
so I listen to Avril Lavigne!
By diversifying both the items and explanation styles, we aim to increase
the probability of a user accepting at least one recommended item.
ES We recommend The Beatles because:
𝑒𝑒𝑒 Last.fm users Anna, Tom, and John with whom
you share similar tastes, listen to The Beatles.
𝑒𝑒𝑒 People who listen to your preferred artist
Bob Dylan also listen to The Beatles.
𝑒𝑒𝑒 The Beatles has similar tags with your
preferred artist The Kinks.
𝑒𝑒𝑒 According to Last.fm, artist The Beatles is
similar to your preferred artist Queen.
𝑒𝑒𝑒 Artist The Beatles is tagged with rock and
band that are in your profile.
𝑒𝑒𝑒 Your friend Lisa likes artist The Beatles.
𝑒𝑒𝑒 Artist The Beatles is very popular in the Last.fm
database with 3.67 M listeners and 516.17 M
playcounts.
Each recommended artist has at most
7 personalized recommendations
generated from explanation styles (ESs).
rock band
𝑒𝑒𝑒
𝑒𝑒𝑒
𝑒𝑒𝑒
pop 90s
𝑒𝑒𝑒
𝑒𝑒𝑒
𝑒𝑒𝑒
pop punk
?
?
?
1st
2nd
3rd
ESs for 𝑎𝑎3: 𝑒𝑒𝑒, 𝑒𝑒𝑒, 𝑒𝑒𝑒, 𝑒𝑒𝑒, 𝑒𝑒𝑒
𝑒𝑒𝑒 is selected because
it is the only ES not
included in either 𝑎𝑎𝑎 or 𝑎𝑎𝑎.
STEP
01 pop
𝑎𝑎𝑎
punk
?
?
𝑒𝑒𝑒 is selected because
it is included in only
dissimilar artist 𝑎𝑎𝑎.
STEP
02 pop
𝑎𝑎𝑎
punk ?
𝑒𝑒𝑒
𝑒𝑒𝑒
𝑒𝑒𝑒
𝑒𝑒𝑒 is selected because
𝑒𝑒𝑒 and 𝑒𝑒𝑒 are included in
both artist 𝑎𝑎𝑎 and 𝑎𝑎𝑎.
STEP
03 pop
𝑎𝑎𝑎
punk
𝑒𝑒𝑒
𝑒𝑒𝑒
𝑒𝑒𝑒
Our method generates a diversified ranked list of ESs for each artist by a greedy algorithm.
Criterion: similar sets of ESs should not be displayed for similar artists.
Metrics
Results
 AILD/EILD: a high value indicates that artists/ESs
in the recommendation list are diversified well.
 WEILD: a high value indicates that
dissimilar sets of ESs are selected between similar artists.
The Beatles
Spice Girls
Avril Lavigne
The Beatles
Spice Girls
Artist-based
Artist-based
Popularity-based
Artist-based
Popularity-based
Artist-based
Artist-based
Tag-based
Tag-based
Artist-based
Popularity-based
User-based
Artist-based
Friend-based
Tag-based
Item: not diversified
Explanation: not diversified
Item: diversified
Explanation: diversified
Item: diversified
𝑎𝑎𝑎
𝑎𝑎𝑎
𝑎𝑎𝑎