Innovative Learning

Aptitude-Treatment Interaction (Cronbach & Snow)

Aptitude-Treatment Interaction (ATI) -- the concept that some instructional strategies (treatments) are more or less effective for particular individuals depending upon their specific abilities. As a theoretical framework, ATI suggests that optimal learning results when the instruction is exactly matched to the aptitudes of the learner. It is consistent with theories of intelligence (e.g., multiple intelligences, intellect theory, triarchic theory) that suggest a multidimensional view of ability.

According to Snow (1989), the aim of ATI research is predict educational outcomes from combinations of aptitudes and treatments. He summarizes the main conclusions of Cronbach & Snow (1977) as: (1) aptitude treatment interactions are very common in education, (2) many ATI combinations are complex and difficult to demonstrate clearly, and no particular ATI effect is sufficiently understood to be the basis for instructional practice. Furthermore, Snow identifies the lack of attention to the social aspects of learning as a serious deficiency of ATI research. He states: "Learning style differences can be linked to relatively stable person or aptitude variables, but they also vary within individuals as a function of task and situation variables." (p51)


ATI research covers a broad range of aptitudes and instructional variables; it has been used to explore new teaching strategies and curriculum design, especially in mathematics and reading.


Snow (1989) states that the best supported ATI effect involves treatments that differ in the structure and completeness of instruction and high or low "general" ability measures. Highly structured treatments (e.g., high level of external control, well-defined sequences/components) seem to help students with low ability but hinder those with high abilities (relative to low structure treatments).


  1. Aptitudes and instructional treatments interact in complex patterns and are influenced by task and situation variables.
  2. Highly structured instructional environments tend to be most successful with students of lower ability; conversely, low structure environments may result in better learning for high ability students.
  3. Anxious or conforming students tend to learn better in highly structured instructional environments; non-anxious or independent students tend to prefer low structure.


Cronbach, L. & Snow, R. (1977). Aptitudes and Instructional Methods: A Handbook for Research on Interactions. New York: Irvington.

Snow, R. (1989). Aptitude-Treatment Interaction as a framework for research on individual differences in learning. In P. Ackerman, R.J. Sternberg, & R. Glaser (ed.), Learning and Individual Differences. New York: W.H. Freeman.

Snow, R., Federico, P., & Montague, W. (1980). Aptitude, Learning, and Instruction, Vols 1 & 2. Hillsdale, NJ: Erlbaum.

Additional Websites

More about ATI research can be found at:
For more about intelligence theories, see