The Personal Beliefs Inventory was used to identify teachers who had strong feelings toward or against the use of experimentation in science classes. Students in the classes of the 16 teachers with the most extreme scores on the Inventory were administered two tests: one class of each teacher was given the Test on Understanding Science and another received the Facts About Science Test. Correlation coefficients between student scores on each test and the teachers score on the Inventory indicated that students who studied biology with "experimental" teachers made superior scores on both tests. The results indicate that open-minded, experimental prone biology teachers consciously or sub-consciously create an atmosphere more conducive to learning science than teachers without strong beliefs toward experimentation. (Author/AL)