Changes in verbalized inquiry behavior of teachers and students who participated in the Mid-Continent Regional Educational Laboratory's Instructional Staff Development program in inquiry were identified. Teachers' verbal behaviors were analyzed in terms of their teaching strategies as related to three inquiry models. An expanded modification of the Flanders' Interaction Analysis Instrument with 34 subcategories was developed and utilized for data collection. Teachers in the program became more indirect in their influence patterns while still leading the inquiry sessions. Pre and posttests resulted in an increase in the number of specific inquiry behaviors and affective areas identified. This reflects a greater understanding of behaviors related to student-centered, inquiry-oriented instruction. As a group, teachers showed a decrease in teacher talk while students exhibited an increase from a pretest of 17.5 to a posttest of 33.5. Teachers also increased their knowledge and application skills on interaction analysis from a mean score of 4.5 to 14.4 out of a possible 19 points on a prepost test. (Author)