In an effort to validate dynamic assessment methods influenced by Vygotsky's (1978) definition of zones of proximal development (an indicator of readiness), three sets of experiments addressed two goals: the development of diagnostic assessment methods and the use of diagnostic results to guide the design of instructional programs. The first two studies examined two psychological processes presumed to be significant predictors of academic performance: acquiring new information (learning) and using that information in novel situations (transfer). Results indicated the validity of the methods used, showing (1) that groups of children of contrasting abilities do differ in terms of learning and transfer, with differences being greater in transfer; and (2) that learning and transfer are better predictors of performance than either IQ or standardized test scores, with the best predictor being transfer. In the third study, which tested the instructional application of dynamic assessment results (emphasizing enhancing the transfer process), subjects taught to use four reading strategies demonstrated gains in their ability to transfer these skills, as evidenced by their standardized and reading comprehension test scores. Results of these studies suggest that the best predictors of the extent to which individuals are likely to profit from instruction are their initial response to instruction (learning) and, even more, how successfully they can transfer their learning to novel situations. Results also suggest the superiority of dynamic assessment over static testing for planning for instruction. A seven-page list of references is included. (LLZ)