Purposes of this study were: (1) to examine patterns of implementation of an innovative educational program with a built-in staff development component over a period of three years; (2) to compare patterns of implementation of the Adaptive Learning Environments Model's (ALEM) three types of teaching skills, including generic, adaptive, and program specific; and (3) to examine site-to-site differences in patterns of program implementation over time. Data for the study were obtained from classrooms in four school districts which implemented the ALEM as the core instructional program in grades K through 3, in conjunction with participation in the National Follow Through Program. Sites varied in ethnocultural, socioeconomic, and geographic characteristics. Teachers' classroom implementation was measured by administration of the Implementation Assessment Battery for Adaptive Instruction (IABAI). Results, obtained using analyses of variance, item analysis, and correlational analysis, were summarized to show few marked differences in patterns of change over time for the three types of teaching skills. When ample support was provided, improvements in implementation were likely to result; the absence of or inadequacy of support, however, lead to stagnation or decrement of teaching skills. (LMO)