5a. attention to the interaction between persons and their environments, especially in reciprocal terms rather than in terms of simple directional causality from teacher to students.
6treating teaching and learning as continuously interactive processes rather than isolating a few factors in the system and labeling them as "cause" and "effect".
7seeing the classroom context as nested within other contexts - the school, the community, the family, the culture - all of which influence what can be observed in the classroom itself.
8treating unobservable processes, such as thoughts, attitudes, feelings, or perceptions ofparticipants, as important sources of data.
9Bracht, G. H. & G. V. Glass. The external validity of experiment[J]. American Educational Research Journal, 1968 (5): 437-474.
10Gordon, B. Cultural comparisons of schooling [J]. Educational Researcher, 1987 (8): 4-7.
