Network & Cluster Analysis of Departmental Libraries Used by

Faculty at a Large University Library

JoAnn JacobyAssociate Professor of Library Administration and

Anthropology & Sociology Subject Specialist

Spiers Estate, South Africa

13-16 August 2007

7th Northumbria International Conference on Performance Measurement in Libraries

& Information Services

• Major research library – big collections (10 million vols.) & great librarians

• Decentralized library system (~40 libraries)• Pressures catalyzing change• User expectations multiplying &

increasingly diverse

Setting: University of Illinois Library

Purpose• Map connections between

departmental libraries from the users’ perspective

• Gain insight into the use of the ~40 libraries by faculty across disciplines

• Evaluate how the library’s structure might be changed to better serve faculty

Methods• Mined data from survey of all faculty,

academic professionals & staff, 2006 <http://www.library.uiuc.edu/assessment/>• Responses to “Indicate your primary

library/ (ies)” were used to create network maps and cluster trees – Respondents could choose as many libraries

as they pleased

Status

Total Head Count

Number of Respondents

Response Rate

(Est.*)

Tenure-Track Faculty 2035 413 20.3%

Visiting Faculty 172 37 21.5% Academic Professionals 2133 647 30.3%

Other (Postdocs, GAs, Classified Staff) 8763* 253 2.9%

All Faculty & Staff 13103* 1350 10.3%

Response Rate

*Distributed by a campus-mediated “massmail,” the survey was sent to 12,399 (not 13103) individuals because the headcount at the time was less than the annual maximum. The response rate was therefore slightly higher than shown.

Social Network Analysis• Seeks to reveal the patterning of

people's interaction (Roger Brown 1965)– Web of social connections key to understanding

individuals, groups & societies

• Studies patterns in the relations social actors have with particular others (Grannis 2005)– Actors can be people, firms, nations, etc.– Relations = whether actors go to war, have sex,

use a particular library, etc.

Methods• Sociomatrix = Data for each relation

presented in a two-way matrix, where the rows & columns refer to the actors making up the pairs.– Format used by most network analysis

software – Adjacency matrix = type of sociomatrix

used for dichotomous data (presence or absence of affiliation)

Methods

Setting up the matrix

MethodsTwo-mode affiliation network

1st mode = 1350 faculty & staff respondents

2nd mode = 47 libraries“Connections among members of one of

the modes are based on linkages established through the second mode”

Affiliations and Overlapping Subgroups. In Social Network Analysis: Methods and Applications. Wasserman & Faust (1994). Cambridge University Press.

Methods

Setting up the adjacency matrix- Quantifies the ties for the relation in question

Network map of connections among all libraries. Lines were drawn when >5 respondents reported

using both libraries. Selected nodes are shown in color.

Software Packages• International Network for Social

Analysis (INSA), “Computer Programs for Social Network Analysis”

<http://www.insna.org/INSNA/soft_inf.html>– Comprehensive list of programs for data

conversion, network analysis, data collection & project management

The INSA website -- a great resource

Pajek <http://vlado.fmf.uni-lj.si/pub/networks/pajek/

default.htm>Free, well-documented, Windows software

TouchGraph <http://www.touchgraph.com/>Commercial source for software &

consulting

BibApp <http://code.google.com/p/bibapp/>Maps researchers & citations 'Institutional

Bibliography'

Drawn by Hand in Adobe Illustrator (>20 only shown here)

Size classes by number of

connections

- Used natural breaks - Basis for circle size

ResultsNetwork maps were generated

showing the connections among:– individual faculty maps– specific departmental libraries – groupings of related

departmental libraries

Individual Respondents

Pink – Cinema Studies, Assistant ProfessorIndigo - Physics, Professor

Green - Agricultural Science (ACES), Academic ProfessionalLight Blue - Spanish, Italian & Portuguese, Associate Professor

Frequency Hisotgram of Number of Libraries Selected

0

50

100

150

200

250

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Number of Libraries Selected

Freq

uenc

y

Specific Libraries

City Planning & Landscape Architecture Library

Modern Languages, Modern Languages, English, English, Classics & Classics & Latin AmericanLatin American

Health Science Library

Broad Disciplinary Groupings

All Divisions coded by color

Life Sciences

Area Studies Arts & Humanities

Physical Sciences & Engineering

Social Sciences

Allied

Special Collections

Central Public Services

Mean Number of Libraries Used by Division

Cluster analysis of all

libraries

Confirms some patterns in the network maps, but is of limited

utility in identifying potential mergers

Correlations with other indicators of activity level

Relationships between Number of Primary Library Designations, Circulation & Web

Transactions

So what?Faculty don’t come in to the library

anymore….

…if they can get what they need online

…..right?

Comments: Library as Place• I mostly use the library via online access…

It's especially great when working at home or doing field research abroad

• Remote delivery of materials is a great service…as my duties make it challenging to get onto central campus to find a book.

• Your questions imply that we actually go to the library and want to interact with librarians

Effect of Online Library Resources by Status

Mode of Library Use by Status

Comments: Library as Place

• Person to person assistance can be key, especially when beginning new projects or trying to navigate through new search tools….

• It would be easier to find print journals and books if the library was open more hours…

• The system of departmental libraries makes it very difficult for an interdisciplinary researcher to find and collect books s/he needs.

Research into Practice• ongoing decisions regarding the

consolidation of library service points• revealing areas of potential

collaboration– e.g., the author collaborated with the

Applied Health Sciences Library (alx) to create a health information portal after seeing evidence of a strong shared constituency

ConclusionsNetwork maps and cluster trees:• reveal connections and patterns

in complex systems• provide a data visualization tool

that can help inform library decision-making

ConclusionsCould be applied to other types of

data:– co-locate/bundle suites of services

frequently used or highly valued by certain groups of library users

– create browsing collections (virtual or tangible) based on “people who checked this out, also checked out”

Questions?