This study assessed the effectiveness of the systematic modeling teaching strategy on integrated science process skills and formal reasoning ability. Urban middle school students received a three-month process skill intervention treatment from teachers trained in either the use of systematic modeling or the learning-cycle model. A third, control group received traditional science instruction. The analysis of data revealed that (a) students receiving modeled instruction demonstrated a significant difference in their achievement of process skills when compared to either of the control groups. (b) Students taught by teachers who had received special process skill and strategy training demonstrated a significant difference in their process skill achievement when compared with the control group. (c) Students at different cognitive reasoning levels demonstrated significantly different process skill ability.