Forty-two university students enrolled in an elementary school language arts methods course were randomly assigned to one of three treatment groups: (1) regular instruction supplemented by micro-teaching technique and videotape, (2) regular instruction supplemented by classroom observation in the public schools, and (3) regular instruction supplemented by the assignment to compile a non-annotated bibliography on language arts. The students' growth in "openness" was measured by the Teacher Problems Q-sort test. Results indicated that only the group participating in micro-teaching experienced a positive and significant growth in openness. The following recommendations were offered: (1) Provide for inclusion of a Micro-Teaching Laboratory in teacher preparation programs. (2) Increase dimensions of research by designing the Laboratory to allow an increased number of lessons to be taught by participants. (3) Provide sufficient videotape to enable storage of all micro-lessons. (Author/LK)