From Kelly (1963): "A range of convenience is that expanse of the real world over which a given system or theory provides useful coverage." [p. 17] "There are, of course, various psychological construction systems. These systems differ primarily because the people who developed them were focusing their attention upon somewhat different events ." [p. 18] "Psycological systems have not only ranges of convenience but also characteristic foci of convenience: points at which they are particularly applicable." [p. 18]
A conceptual framework of learning on which domain-specific, individualized, theories of learning can be constructed.