Invited discussion of Cronbach (1951) Coefficient alpha and the internal structure of tests. Psychometrika, 16, 297 334 (26,889 citations in Google Scholar as of 1/1/2016)
"By far the most cited article in Psychometrika is Lee Cronbach's famous study of coefficient alpha. I will address four questions: What makes the article special? Why do people cite the article more than other special articles? Was the article also influential beyond psychology? How does alpha fit in present day psychometrics?"