When student teachers experience difficulty during lesson implementation, seasoned cooperating teachers choose among 6 alternative strategies by which to assist. Collectively called "cooperating teacher I's," the strategies are as follows: ignore, intervene, interject, interact, interrupt, and intercept. Appropriate use of these strategies can be taught directly or made more explicit to cooperating teachers as a means to facilitate quick resolution of problems; maintenance of student teacher confidence, self-esteem, and classroom authority; cooperating teacher confidence in the mentor role; and active or passive choices as they may be appropriate to specific circumstances. Included is a brief summary of research about cooperating teachers and their feedback practices, a description of behaviors that generally prove to be ineffective in response to these situations, detailed descriptions of the 6 cooperating teacher I's that appear to be effective, and a discussion of general observations and implications. (Contains 1 table and 2 notes.)