Components of Variance of Scales With a Bifactor Subscale Structure From Two Calculations of α

Since Cronbach's (1951) elaboration of α from its introduction by Guttman (1945), this coefficient has become ubiquitous in characterizing assessment instruments in education, psychology, and other social sciences. Also ubiquitous are caveats on the calculation and interpretation of this coefficient. This article summarizes a recent contribution (Andrich, 2015) on the use of coefficient α which complements these many caveats. It shows that in the presence of a simple bifactor structure of a scale where unique components of variance are homogeneous in magnitude, three components of variance and the common latent common correlation among the subscales can be calculated from the ratio of two calculations of α, one at the level of the items, the other at the level of the subscales. It was suggested that these two ready calculations and their interpretation, and the reporting of all four indices in the analysis of scales with a subscale structure, would reduce the misinterpretation of this coefficient. An illustrative example of the application of the calculations is also shown.     

Using Consumer Data to Illustrate How the Library Channel Drives Digital Sales

The library channel is often underappreciated as a key part of a publisher’s business strategy. In an age where publishers are constantly seeking new revenue and marketing opportunities, presence in the library—digitally—can yield significant growth. This paper examines the library channel, its business model based on library lending, the performance of eBooks and audiobooks across all subjects, and consumer reading behavior. Digital Book Clubs, a relatively new phenomenon, are also defined and illustrated with examples demonstrating the library’s valuable role in increasing discoverability and ultimately sales.     

The Teaching of French as a Mother Tongue

The 14th International Week of Educational and Teaching Films organised this year, as in 1976, for ICEM, by the Belgian Ministry of National Education and Culture, took place from 17 to 21 April in the Quality Inn Hotel, Antwerp. It was attended by 80 participants, the strong European contingent being joined by North Americans, Kuwaitis, Australians and Japanese.     

DIRECT NON‐VIOLENT ACTION AND THE LAW

This article was delivered as the plenary address at the Massachusetts Association for Bilingual Education Annual Conference, November, 1986. The style of the speech has been preserved.