This study compares 3rd-grade elementary students' gain and retention of science vocabulary over time in two different classes--"connected science instruction" versus "direct instruction." Data analysis yielded that students who received connected science instruction showed less gain in science knowledge in the short term compared to students who received direct instruction. On the other hand, the growth curve demonstrated a lower rate of loss of science knowledge among students in connected science classes compared to students in direct instruction classes. (Contains 2 tables and 1 figure.)