Psychologist and authority in educational measurement, Benjamin Bloom has influenced a whole generation of researchers. His research into the importance of early childhood education has challenged educators to reconsider present procedures for organising schools and allocating resources. His recent work on Mastery Learning promises to open a new set of approaches to the education of all children. 1
Benjamin S. Bloom was born in Lansford, Pennsylvania in 1913 into a Jewish family which had emigrated from a climate of discrimination in Russia a few years earlier. The father was a poor tailor and Ben like many others with his background wanted to become a teacher, a way of climbing the social ladder. After graduation from Pennsylvania State College in 1935 he became a research assistant in the American Youth Commission. After a short stay with the Cooperation Study in General Education he became employed in the historical Eight-Year Study by Ralph Tyler who at the time had become chairman of the School of Education at the University of Chicago. He enrolled in the doctoral programme there and completed his Ph.D. in 1942. After serving as a researcher on the Board of Examiners at the University of Chicago; and as examiner at the college of the University, Bloom became Professor of education in Chicago in 1940. He stayed there until retirement in 1990. Early in his career, Bloom became involved in international projects in India and Israel and was one of the founding members of the International Association for the Evaluation of Educational Achievement (IEA) in 1961. He belonged to the Panel that established the Research and Development Centres in the US in the 1960s and served as Chairman of the American Educational Research Association (AERA) 1965-66. Among his many recognitions was his receipt of the AERA-Phi Delta Kappa Award for distinguished contributions to education in 1970.
Working under Ralph Tyler, Bloom gained deep insights into the theory and practice of educational evaluation, a term coined by the task that evaluators set themselves. Bloom set about the task of translating the goals of instruction via concrete behaviours into instruments of measurement, a task that was particularly difficult when one had to deal with goals in the affective domain, i.e. in assessing attitudes and interests. In the 1950s he served as chairman of a committee on taxonomy of educational objectives set up by the AERA. The first book, covering the cognitive domain, authored by Bloom and David Krathwohl, Taxonomy of Education Objectives, was published in 1956. Another eight years elapsed until volume II, covering the affective domain, came out in 1964.
In the late 1960s Bloom began to develop a theory of 'mastery learning'. According to this theory the great majority of students, say 90-95 per cent, are able to learn basic principles, concepts and skills-if they are given enough time. Bloom's point of departure for research on mastery learning was the model of school learning which has been advanced by John Carroll at Harvard University and later Educational Testing Service in Princeton. According to Carroll the most important differentiating factor behind school achievement was time not differences in some kind of scholastic