Paper: The Literature Review of Technology Acceptance Model: A Study of the Bibliometric Distributions by Chang et al.

Summary and review:

This paper is about bibliometric study of publications in the field of "Technology Acceptance Model" (TAM) for information systems(IS).
what is TAM:TAM is a very influential and common theory in information systems field, it explains the user adoption of technology use in different environment setting. TAM is based on theory of reasoned action which discusses how attitude impacts behaviour. The model suggests that when users are presented with a new technology, a number of factors influence their decision about how and when they will use it, notably:
Perceived usefulness (PU) - This was defined by Fred Davis as "the degree to which a person believes that using a particular system would enhance his or her job performance".
Perceived ease-of-use (PEOU) - Davis defined this as "the degree to which a person believes that using a particular system would be free from effort" (Davis 1989).[4]

The work:

several papers were collected using “technology acceptance model” keyword and 689 related articles were selected after filtering the original list. these papers were published between 1991-2009.

study shows that number of published papers in this topic grew steadily in this period.

The authors who published TAM literature are from 41 countries. The U.S.A. with 37.32% of total is the primary country to contribute to this field.

disciplines:
TAM is used in variety of disciplines such as:
Computer Science, Information Systems”, “Management”, “Information Science & Library Science”, “Business” and “Computer Science, Cybernetics” 

keywords:most frequent keywords extracted from papers, reflecting the subject areas:
Technology Acceptance Model (TAM)
Electronic commerce
Internet(Web)
Structural equation modeling(SEM)
Perceived usefulness, Usefulness
Trust
Theory of planned behavior (TPB)
E-learning

Bradford Law and Core JournalThrough the 174journals that published TAM papers, 98 journals only published one article.
The result matches the explanations of Bradford’s Law. It indicates the publication of TAM in these journals account for one-third of the total amount.

Author Productivity and Lotka’s Law 

There are total 1692 authors (shown in table 3) contributing to the publications of 689 articles in TAM literatures. According to this data set, 988 authors (58.39%) contributed one article. It is consistent with the Lotka's law that about 60% authors contribute only one paper. The maximum of articles by one author is 14, followed by 11 and 9. the results indicated that the author productivity distribution data in TAM literature consistent with Lotka’s law.

more details on methods used in this paper:

bibliometric methods are a set of methods to quantitatively analyse academic literature, Many research fields use bibliometric methods to explore the impact of their field, the impact of a set of researchers, or the impact of a particular paper.[1]

Two theory is used to achieve this goal:
Lotka’s law which talks about authors impact and productivity in the field.
It describes the frequency of publication by authors in any given field. It states that the number of authors making n contributions is about 1/n^a of those making one contribution, where a nearly always equals two. More plainly, the number of authors publishing a certain number of articles is a fixed ratio to the number of authors publishing a single article. As the number of articles published increases, authors producing that many publications become less frequent. There are 1/4 as many authors publishing two articles within a specified time period as there are single-publication authors, 1/9 as many publishing three articles, 1/16 as many publishing four articles, etc. Though the law itself covers many disciplines, the actual ratios involved (as a function of 'a') are very discipline-specific[3]
y=c/x^n
where y=percentage of authors, x=number of articles published by an author, c=constant and -n=slope of the log-log plot


Bradford’s law that estimates the exponentially diminishing returns of extending a search for references in science journals. One formulation is that if journals in a field are sorted by number of articles into three groups, each with about one-third of all articles, then the number of journals in each group will be proportional to 1:n:n².[2]
Bradford’s law is a regular pattern over a huge number of articles from different journals on a particular subject. concentrated in a small number of journal titles, and the remaining articles would be distributed over the vast account of journal titles



1.http://en.wikipedia.org/wiki/Bibliometrics
2. Black, Paul E. (2004-12-12). "Bradford's law, in Dictionary of Algorithms and Data Structures". U.S. National Institute of Standards and Technology. Retrieved 2007-10-24.
3.http://en.wikipedia.org/wiki/Lotka%27s_law
4.http://en.wikipedia.org/wiki/Technology_acceptance_model