Bibliometric research methods Faculty Brown Bag IUPUI Cassidy R. Sugimoto

Overview Vocabularly Citation analysis Citation indices Bibliometric laws Impact factor Applications

Vocabulary Scholarly Communications  Formal and information Scientometrics  Scientific communication Infometrics  Thinking beyond scholarly “texts” Webometrics  web Bibliometrics  Application of statistical and mathematical methods (formal channels)

Citation analysis Why do people cite? Why are some articles not cited? What does a citation mean? Citing document Cited document B is cited by A AB A references B

Who’s on first? Embedded citation index from ` En mishpat: Babylonian Talmud (1546) (Weinberg, 1997) Shepard’s Citation Index (1873) Shapiro (1992)

Institute for Scientific Information (ISI)

Scopus

GoogleScholar

Comparison Overlap 57% (4,892) Scopus 29% (2,441) Web of Science 14% (1,216) Scopus n=7,333 (86%) Web of Science n=6,108 (71%) Distribution of unique and overlapping citations in Scopus and Web of Science (n=8,549)

Are you a citation index?

Bibliometric research OR “Why I love good indexes”

Citation analysis Citing document Cited document B is cited by A AB A references B

Citation analysis: methods Not just articles…

Variable:PRODUCERS

Variable:ARTIFACTS

Variable:CONCEPTS

Hybrid approaches Chaomei Chen:

h-index Hirsch (2005)  A scientist has index h if h of [his/her] N p papers have at least h citations each, and the other (N p − h) papers have at most h citations each.

Bibliometric laws Lotka’s Law (1926) the number (of authors) making n contributions is about 1/n² of those making one; and the proportion of all contributors, that make a single contribution, is about 60 percent (60,15,7…6>10) Not statistically exact May be changing with the current model of scholarship

Bibliometric laws Bradford’s law (1934) Journals in a field can be divided into three parts: 1)Core: relatively few # of journals producing 1/3 of all articles 2)Zone 2: same # of articles, but > # of journals 3)Zone 3: same # of articles, but > # of journals The mathematical relationship of the number of journals in the core to the first zone is a constant n and to the second zone the relationship is n². 1:n:n² Not statistically exact General power law distribution (akin to Pareto’s law in economics)

Bibliometric laws Zipf’s Law (1935) Not statistically exact General power law probability distribution listing the words occurring within that text in order of decreasing frequency, the rank of a word on that list multiplied by its frequency will equal a constant. The equation for this relationship is: r x f = k where r is the rank of the word, f is the frequency, and k is the constant James Joyce's Ulysses 10 th most frequent: 2,653 times 100 th most frequent: 265 times 200 th most frequent: 133 times rank of the word multiplied by the frequency of the word equals a constant that is approximately 26,500

Bibliometric laws Other power law probability distributions  Pareto’s law (economics) rule Law of the vital few Principle of factor sparsity  PageRank (google)  The Long Tail (markets)

Journal impact factors

As a research method… Reliability? Validity? Limitations?

Applications? Finding and use Collection development Reference services Collection evaluation  Use studies Information retrieval algorithms Diffusion of ideas Domain areas and interdisciplinarity Mapping science

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