Research suggests that preservice training has at best only a modest impact on a teacher's later teaching. The fundamental behaviors of a beginning teacher apparently originate from sources other than the training program. A study sought to identify the origins of first-year and student teacher behaviors and to define these behaviors more directly and precisely than previous studies have done. Six trained observers visited 44 first-year teachers (both elementary and secondary school) and 27 student teachers (elementary school only) approximately 8 times. While in the classroom, the observer recorded happenings in five areas: (1) teacher directions; (2) presentation of information; (3) questioning strategies; (4) evaluative feedback; and (5) materials and equipment used. Student attention levels were recorded when transitions were made from one activity to another. Immediately after each observation period, the teacher was interviewed, presented with a summmary of class activities, and asked why they did the things they did. Other data gathering techniques on teacher behaviors included: activity forms; generic source forms; student interviews; and student work and achievement data. Results suggest that teachers rely more upon their own experience than on their formal training as the basis for their teaching practice. Reasons for this are discussed, and teaching behavior origins are outlined in 16 graphs and tables. (JMK)