A bibliometric study of differential item functioning

Summary

This study presents a bibliometric analysis of scientific output in the area of Differential Item Functioning (DIF), the aim being to offer an overview of research activity in this field and characterise its most important aspects and their evolution over the last quarter of the 20th century, thus providing data regarding the basis on which this activity is being developed at the beginning of the 21st century. The analysis makes use of the Web of Science database, the search being restricted to articles published between 1975 and 2000 and which contain the terms ‘differential item functioning’, ‘DIF’ or ‘item bias’. The various analyses focus on the presentation of publication frequencies and percentages, as well as on the application of Bradford’s law of scattering and Lotka’s law.