For many years, it seems that the prevailing view of education
was that, provided instruction was of reasonable quality, it need
not be adaptive to the needs of learners. It was assumed either that
well-designed instruction would be effective for the majority of
students for whom it was intended (with others being assigned to
remedial activities) or that the causes of any failures to learn lay
within the individual learner (the material was just too hard for
them, and they should instead pursue other, and generally less
academic, avenues). However, in the 1960s, Benjamin Bloom and
his graduate students at the University of Chicago began to explore
the idea that the normal distribution of student outcomes was not
a ‘‘natural’’ outcome, but caused by the failure of the instruction to
recognise differences in learners