Cognitive Differences:

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


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


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

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


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


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



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


• User Interface - List


• 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)


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.


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


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


“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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Documents

Cognitive Differences: