Talk given at the IEEE Symposium on Visual Analytics Science & Technology (VAST), 2009.

1. Finding&Comparable&&
Temporal&Categorical&Records:&
A"Similarity"Measure"
with"an"Interac4ve"Visualiza4on"
Krist&Wongsuphasawat&
Ben&Shneiderman&
Dept."of"Computer"Science"&"Human@Computer"Interac4on"Lab"
University"of"Maryland"

2. Temporal&categorical&data&
! A"type"of"4me"series"
! Comparison"
Numerical Categorical
e.g. stock indices e.g. patient histories
10/8/2007 !540.35! 10/8/2007 !Respiratory!
10/9/2007 !555.32! 10/9/2007 !Mental Disorder!
... ...

3. Temporal&categorical&data&(2)&
! Examples"
" Electronic"Health"Records"
" Traffic"incident"logs"
" Student"records"

4. Finding&similar&records&
! E.g."Find"pa4ents"with"similar"symptoms"
"to"guide"the"treatment."

5. Finding&similar&records&(2)&
! How?"
" Users"specify"one"target"pa4ent"
" Similarity"Measure"
# Gives"a"score"that"shows"how"much"two"records"are"
similar.""
# Score"ranges"from"0"to"1."(Most"similar"="1)""

6. Finding&similar&records&(3)&
Patient #1 Patient #2 0.80
(target)
Patient #3 0.63
Patient #4 0.96
Patient #5 0.77

7. Finding&similar&records&(4)&
Patient #1 Patient #4 0.96
(target)
Patient #2 0.80
similar
Patient #5 0.77
Patient #3 0.63

8. Challenge&
! What"is"“similar”?" depends"on"users/tasks"
Patient#1
(target) A B C
Patient#2 missing
A B C
Patient#3 extra
A B C D
Patient#4
Time difference
A B C
time

9. Related&work&
! Similarity"measure"
" Similarity"measure"for"numerical"4me"series"
# [Ding"et"al."2008],"[Saeed"and"Mark"2006],"..."
" Edit"distance"
# [Levenshtein"1966],"[Winkler"1999],"..."
" Biological"sequence"searching"
# [Pearson"and"Lipman"1988],"[Altschul"et"al."1990],"...""
! Visualiza4on"
" Temporal"visualiza4on"
# [Wang"et"al."2008],"[Plaisant"et"al."1998],"..."
" Rank@by@feature"framework"
# [Seo"and"Shneiderman"2005]"

10. Alignment&
! Sen4nel"events"
Time
June July August
Patient #45851737 Admit
Emergency
ICU
Floor
Exit
Patient #43244997 Admit
Emergency
ICU
Floor
Exit

11. Alignment&(2)&
! Time"shicing"
Time
0 1M 2M
Patient #45851737 Admit
Emergency
ICU
Floor
Exit
Patient #43244997 Admit
Emergency
ICU
Floor
Exit

12. In&this&paper,&we&propose&
! M&M"(Match"&"Mismatch)"measure"
" A"similarity"measure"
! Similan"
" An"interac4ve"visualiza4on"

13. M&M&Measure&
time
Patient#1
(target) A C B C
Patient#2
A B C B
Matched Events Missing Event Extra Event
Match Score = F(time difference)
Mismatch Score = F(Number of Mismatches) } Total Score
0 to 1

14. Similan& Comparison Panel Control Panel
! Layout"
Ranking Score
Main Panel
Plot Panel

15. ScaHerplot&
+
+
+
Number of Mismatches
0
1 Match Score 0

16. Usability&study&
! 8"par4cipants"
! Goals"
" Examine"learnability"of""Similan"
" Assess"the"benefits"of"a"scaeerplot"
" Observe"users’"strategy"
! Tasks"
" Find"5"persons"that"are"most"similar"to"the"target"

17. Results&
! Easy"to"use,"but"some"interface"issues"
! Scaeerplot"
" Different"opinions"
" Give"overview"
" Explain"how"records"are"dissimilar"
! Strategy"
" Select"target"
" Rank"by"total"score"
" See"comparison"

18. Ongoing&work&
! More"customizable"similarity"measure"
! Flexible"query,"Query@by@Example"
! Improve"user"interface"

19. Note: recent work / not in the paper
http://www.cs.umd.edu/hcil/similan

20. Similan&
! Demo"
! Data""
" from"Washington"Hospital"Center"
" ICU"(Intensive"Care"Unit)"pa4ent"transfers"
" deiden4fied"

21. Conclusion&
! Problem"
" Finding"similar"temporal"categorical"records"
" What"is"similar?"
! Contribu4ons"
" M&M"measure"
" Similan"
! Ongoing"work"
" More"customizable"similarity"measure"
" Flexible"query,"Query@by@Example"

22. More...&
! Contact"
" kristw@cs.umd.edu"
" hep://www.cs.umd.edu/hcil/similan"
! InfoVis"“Space"and"Time”"session"
" Thursday"2:00@3:40pm"
&Temporal&Summaries:&SupporMng&Temporal&Categorical&
Searching,&AggregaMon&and&Comparison&
"Taowei"David"Wang,"Catherine"Plaisant,"Ben"Shneiderman,"
Neil"Spring,"David"Roseman,"Greg"Marchand,"Vikramjit"
Mukherjee,"Mark"Smith""

23. Thank&you&