In the early 1900's american psychology shifted its emphasis from (one word) in the academic laboratory to the application of psychology to the issues of teaching and learning.

Emphasis was shifted from experiments in the academic laboratory to the application of phycology to the issues of teaching and learning.

Transition took place from controlled environments to focusing the interest on real ones, each of them totally different from others and where external conditions affect human reactions, for example, the socioeconomical, cultural or familiar conditions of students in teaching and learning processes are going to affect their responses to the metodologies they are exposed to. This cannot occur in an artificially controlled environment such as a laboratory.

industry had made the u.s. the richest nation in the world at this time. the second industrial revolution caused growth in industry and transportation, which allowed increased trade between nations.