Cognitive Differences: Personal characteristics facet
Jacek GwizdkaAssistant ProfessorDepartment of Library and Information Science
CONTACT:
www.jsg.tel
What types of cognitive differences?
• Cognitive ability – refers to some aspect human ability to perform cognitive tasks, that is, tasks ‘in which correct and appropriate processing of mental information is critical to successful performance’ (Carroll, 1993)
– Best known systems of cognitive abilities is Carroll’s 3-stratum theory– Examples of cognitive abilities: Working memory, Spatial ability, Verbal closure
• Cognitive style – personality dimension that influences how people collect, analyze, evaluate, and interpret information (Harrison & Rainer, 1992)
– Example of cognitive style: field dependence / field independence (FD/FI)
What is being personalized?
• Information presentation• Information interaction style
Individual Differences – Example 1
Cognitive differences and information finding in web
directories
Individual Differences – FD/FI : definition
FD FIholistic perception (whole objects) analytic perception (parts)
global focus focus on detail
external references internal references
passive in locating information active in locating information
Cognitive Style: field-dependence / independence (FD / FI)
Witkin et al. (1971)
Individual Differences – FD/FI : implications
FD FI
less information more (dense) information
externally imposed structure own structure
extra guidance locate info directly
sorted by relevance alphabetical organization
category / sub-category organization
breadth (more main cats, less sub-cats) depth (less main cats, more sub-cats)
separate category levels category levels shown together
Cognitive Style: field-dependence / independence (FD / FI)
Example 1 – Web Directory PresentationField Dependent Field Independent
From: Chen, S. Y., Magoulas, G. D., & Macredie, R. D. (2004). Cognitive styles and users’ responses to structured information representation. International Journal on Digital Libraries, V4(2), 93-107.
sorted by relevancesorted by relevance sorted alphabeticallysorted alphabetically
one level of categoriesone level of categoriesmultiple levels of categoriesmultiple levels of categories
Individual Differences – Example 2
Cognitive differences and information keeping in & out of
From: Gwizdka, J. (2004). Email task management styles: The cleaners and the keepers. CHI '04 Extended Abstracts on Human Factors in Computing Systems, Vienna, Austria. 1235 - 1238. : ACM Press. DOI: 10.1145/985921.986032 http://bit.ly/email_keep_clean
Individual Differences – FD/FI : definition
FD FIholistic perception (whole objects) analytic perception (parts)
global focus focus on detail
external references internal references
passive in locating information active in locating information
Cognitive Style: field-dependence / independence (FD / FI)
Witkin et al. (1971)
Example 2 – Information Keeping in Email
Email Habit Variables The Cleaners The Keepers
Keep events in email no yes
Keep to-do's in email no yes
Search in email no yes
Can we relate difference in email habits with cognitive styles?
The Cleaners: transfer time sensitive messages (e.g., to-do’s) from email The Keepers: keep time sensitive messages in email
From: Gwizdka, J. (2004). Email task management styles: The cleaners and the keepers. CHI '04 Extended Abstracts on Human Factors in Computing Systems, Vienna, Austria. 1235 - 1238. : ACM Press. DOI: 10.1145/985921.986032 http://bit.ly/email_keep_clean
Example 2 – Information Keeping in Email
Email Habit Variables The Cleaners The Keepers
Keep events in email no yes
Keep to-do's in email no yes
Search in email no yes
Can we relate difference in email habits with cognitive styles?
The Cleaners: transfer time sensitive messages (e.g., to-do’s) from email The Keepers: keep time sensitive messages in email
Field dependent Field independent
From: Gwizdka, J. (2004). Email task management styles: The cleaners and the keepers. CHI '04 Extended Abstracts on Human Factors in Computing Systems, Vienna, Austria. 1235 - 1238. : ACM Press. DOI: 10.1145/985921.986032 http://bit.ly/email_keep_clean
Individual Differences – Example 3
Cognitive differences and information finding search results overview (tag
cloud)
Gwizdka, J. (2009). "What a difference a tag cloud makes: effects of tasks and cognitive abilities on search results interface use" Information Research, 14(4) paper 414 http://bit.ly/tagcloud_search
Individual Differences – Example 3
• User Interface - List
Individual Differences – Example 3
• User Interface – List + Overview
Example 3 – Information Finding using Overview
• Cognitive ability: Verbal Closure = The ability to identify visually presented words when some letters are missing, scrambled, or embedded among other letters (Ekstrom, 1976).
• Overview made low verbal closure people more efficient (38 vs. 60 seconds per query reformulation)
• Overview made high verbal closure people faster (146s vs. 240s, at the same level of efficiency ~33s per query reformulation)
Gwizdka, J. (2009). "What a difference a tag cloud makes: effects of tasks and cognitive abilities on search results interface use" Information Research, 14(4) paper 414 http://bit.ly/tagcloud_search
Yes, Individual Differences - So What?
Approaches:
• provide alternative interfaces for different users
• create interfaces that can be adapted by users
• create interfaces that adapt to users
© Jacek Gwizdka 17
Thank You
Questions?Jacek Gwizdka
Dept. of Library & Information ScienceSchool of Communication and Infromation
Rutgers UniversityNew Brunswick, NJ, USA
http://www.jsg.tel
http://www.comminfo.rutgers.edu/~jacekg/http://www.gwizdka.com
This research was partially funded by a grant from IMLS: LG-06-07-0105-07“Personalization of the Digital Library Experience”
Cognitive Load and Web Search Tasks
• Understand mental demands of search tasks and interfaces
user interface differences: L
higher peak cognitive load: C
higher averagecognitive load: Q & B
CONTACT:
www.jsg.tel
Example 3 – Information Finding using Overview
• Cognitive ability: Verbal Closure = The ability to identify visually presented words when some letters are missing, scrambled, or embedded among other letters.
Gwizdka, J. (2009). "What a difference a tag cloud makes: effects of tasks and cognitive abilities on search results interface use" Information Research, 14(4) paper 414 http://bit.ly/tagcloud_search
Low Verbal Closure High Verbal Closure
List 238 4 240 7
Overview (list + tags) 206 5.5 146 4.5
59.5 34.3
37.5 32.4
Individual Differences – Example 5
Cognitive differences and information scanning (in email)
Example 5 - Scanning Email MessagesScanning Task: find message in inbox based on partial header infoDifferences in cognitive abilities: working memory WM, visual memory VM, flexibility
of closure CF
UI-”Visual” UI-”Text”
(Gwizdka, CASCON’2002, PhD’2004, Interacting with Computers’2004)
Example 5 - Scanning Email Messages
• better visual memory • (mv1 & mv2)
less scrolling
• better working memory• (wm)
less sorting
better • flexibility of closure
• (cf2)
more scrolling-1.0 -0.5 0.0 0.5 1.0Factor1
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
Fa
cto
r2
cf2
mv1
mv2
wmahc1
scrollt
scrollctscrolldt
scrollmt
sorttot
sorttoct
sorttodt
sorttomt
Sorting
Scrolling
CF
WMMV2
MV1
Individual Differences - Example 4
Cognitive differences and information search (different search engines and
interfaces)
© Jacek Gwizdka 25
Individual Differences – Example 4
“plain”result listGoogle
“faceted” search - ALVIS
Example 4: Results cognitive ability and UI
Working Memory (WM) influenced task performance on ALVIS, but not on Google
• hi-WM more search effort on ALVIS (more pages, more bookmarks, spent more time) than on Google
• lo-WM less effort on ALVIS than on Google
Google ALVIS
search effort
high WM
low WM
Cognitive Differences (Personal characteristics facet; Task facet)
• People differ with respect to their information processing ability and their preferred cognitive style. These differences affect how they interact with information search systems. I argue that personalization should take into account a whole range of factors, including the person’s cognitive abilities. In the world of scarce attention, a system that does not match cognitive abilities may require extra cognitive processing and impose an unnecessary cognitive load. This extra load may prevent the person from completing their information tasks and may even lead to the system avoidance or abandonment. I will present some findings that demonstrate the effects of the cognitive differences among people on their execution of information tasks.
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