The Use of Usage Michael J. Kurtz Harvard-Smithsonian Center for Astrophysics

Collaborators Johan Bollen Edwin Henneken Alberto Accomazzi

Literature all in arXiv 2013 Kurtz & Henneken, “Finding and Recommending Scholarly Articles” in Bibliometrics and Beyond, MIT Press 2010 Kurtz & Bollen, “Usage Bibliometrics” Ann Rev Information Science & Tech 2005 Kurtz et al. “Bibliometric Properties of Article Readership Information” J. Am Soc Information Science & Tech

Four Types of Readers Researchers (=authors?) Practitioners Students General Public

General Public (Google)

Students (Google Scholar)

Co-Usage Recommendations – What are people like me reading – What are people who read this also reading Queries – Sort by most downloaded – Sort by filtered downloads

Scholarly Articles Are Different Scholarly Articles are MUCH denser than films Netflix ~ 25,000 films ADS ~ 10,000,000 articles – 172,000 contain the word “cosmology” – >12,000 in 2012

Scholarly Articles Are Different Scholarly Articles are read by scholars Typically they have subject matter doctorates Their needs are often highly specific There are not many of them

Usage vs Age – 90 weeks

Aggregation Articles Readers Enhance Signal to Noise Engineering Issues – What are you trying to achieve – Who are you doing this for – How fast must it be

What Can Be Measured The Interconnectedness of Science Fields of Study Countries Journals Organizations People Instruments Articles

Usage map 200M usage events 2006 usage only JCR journals ( ) Red, orange= psych, cogn Green = phys, chem Olive = material science Blue = biology Purple = pharma Bollen et al, 2009a

Networks - ADS

Weak Lensing (84)AGN Spectra (101) Comparing Sub-Fields

Measuring Countries Authors are from countries, reads as a function of author’s country has yet to be studied Readers are from countries, their activities allow one to measure the Scientific Wealth of Nations

ADS use vs per capita GDP

Astronomy is representative ADS predicts average of Cites+articles better than cites predicts articles

Measuring Changes

Measuring Journals Beyond the Impact Factor Reads vs Cites differences will be important here The New York Times would have a low Impact Factor

Standard Usage Measures COUNTER David Nicholas, Ian Rowland & collaborators University College, London CIBER-Research

Bollen et al, 2009b

Measuring Departments

Department Size Can Matter

BerkeleyPrinceton

Measuring Individuals The number of times one’s articles are read is a valid measure of one’s scientific impact, similar to citation counts Use has different properties than cites, together they form a two dimensional view of productivity

The Read-Cite Diagram

Professional Astronomers

2 dimensional productivity model

Different productivities - histories

Productivity vs Age - Cites

Productivity vs Age - Reads

Reads and Cites History for M. Kurtz

Papers, Reads, and Cites for Hectospec

Papers, Read, Cites for NAG5-4445

Reads, Cites for 1998PASP K

Final Thoughts Much remains to be done – Implement “best” methods – Develop standard data Problems abound – Privacy – Open Access – Who exactly is reading this paper? – Why do I care? (not money)