The terms applicability, generalizability, external validity and transferability are related, sometimes used interchangeably and have in common that they lack a clear and consistent definition in the classic epidemiological literature. However, all of these terms generally describe one overarching theme: whether or not available research evidence…

The effects of two or three years of a sequential educational intervention program on culturally deprived children were studied with two groups of four-year-olds and two groups of five-year-olds. They were matched on several developmental variables, with one group at each age level entering the experimental Learning to Learn Program. The other…