Cognitive Differences:

Cognitive Differences: Personal characteristics facet Jacek Gwizdka Assistant Professor Department 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 Cognitive Style: field-dependence / independence (FD / FI) FD holistic perception (whole objects) global focus external references passive in locating information

Witkin et al. (1971)

FI analytic perception (parts) focus on detail internal references active in locating information

Individual Differences – FD/FI : implications Cognitive Style: field-dependence / independence (FD / FI) FD less information

FI 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)

separate category levels

depth

(less main cats, more sub-cats)

category levels shown together

Example 1 – Web Directory Presentation Field Dependent

Field Independent

sorted by relevance

one level of categories

sorted alphabetically

multiple levels of categories

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.

Individual Differences – Example 2 Cognitive differences and information keeping in & out of 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

Individual Differences – FD/FI : definition Cognitive Style: field-dependence / independence (FD / FI) FD holistic perception (whole objects) global focus external references passive in locating information

Witkin et al. (1971)

FI analytic perception (parts) focus on detail internal references active in locating information

Example 2 – Information Keeping in Email Can we relate difference in email habits with cognitive styles? The Cleaners: transfer time sensitive messages The Keepers: keep time sensitive messages

Email Habit Variables

(e.g., to-do’s)

from email

in email

The Cleaners

The Keepers

Keep events in email

no

yes

Keep to-do's in email

no

yes

Search in email

no

yes

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 Can we relate difference in email habits with cognitive styles? The Cleaners: transfer time sensitive messages The Keepers: keep time sensitive messages

(e.g., to-do’s)

from email

in email

Field dependent

Field independent

The Cleaners

The Keepers

Keep events in email

no

yes

Keep to-do's in email

no

yes

Search in email

no

yes

Email Habit Variables

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

Thank You Questions? Jacek Gwizdka Dept. of Library & Information Science School of Communication and Infromation Rutgers University New 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” © Jacek Gwizdka

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Cognitive Load and Web Search Tasks • Understand mental demands of search tasks and interfaces

higher average cognitive load: Q & B

CONTACT:

www.jsg.tel

higher peak cognitive load: C

user interface differences: L

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.

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

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 5 Cognitive differences and information scanning (in email)

Example 5 - Scanning Email Messages Scanning Task: find message in inbox based on partial header info Differences 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) 1.0

scrolldt

0.8

  less scrolling

scrollt

Scrolling

scrollct

CF

• better working memory

0.6

• (wm)

scrollmt

 less sorting

cf2

0.4

r2 to c a F

sorttodt

WM

0.2

0.0

wmahc1

MV1

MV2

sorttoct

Sorting

sorttot sorttomt mv2

-0.2

-0.4 -0.5

0.0

0.5

• (cf2)

  more scrolling

mv1

-1.0

better • flexibility of closure

1.0

Individual Differences - Example 4 Cognitive differences and information search (different search engines and interfaces)

Individual Differences – Example 4 “plain” result list Google

“faceted” search - ALVIS

© Jacek Gwizdka

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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 search effort

high WM

low WM Google

ALVIS

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.   27