tin the comments section of a course evaluation a student once wrote, sleep throughout most of my Biology lectures. My professor tries hard but I just get tired of listening to so much information. This was the end of the spring semester of 1998, and I suddenly realized that I had to change the way I taught! This realization took me a long time, for in the past decade educators have been concerned with the way science is being taught, and several national efforts have been directed to redesign the instruction of pre-college science courses (AAAS, 1993, 1994; NRC, 1996). The main concern was that traditional science teaching has relied primarily on lecturing facts, and frequently requires memorization of long lists of specific vocabulary (Leonard et al., 2001). In general, the results of such teaching have been in lack of student motivation for the sciences, and limited learning reflected on poor content retention, few scientific skills, and inability to apply concepts. When professors started to examine college instruction, they found that the same traditional teaching model was followed throughout the universities, and identified serious repercussions on the quality of science education acquired by higher level students (Adams & Slater, 1998; Anderson, 1997; Rice, 1996; Yager, 1991). Thomas Lord (1998) questioned why college students demonstrated difficulty when making connections between concepts that they had learned before, or when applying their knowledge to problemsolving situations. He thought that these problems might be a consequence of the traditional way science courses were taught, because the traditional method does not provide time for discussion, or engagement of students on inquiry-based exercises. Subsequently, Lord dramatically modified his method of instruction. Lord's innovative teaching method is student-centered and uses constructivism, active teaching, and cooperative groups. His method has proven effective in lectures and laboratories for General Biology and Environmental Science at Indiana University of Pennsylvania (Lord, 1997, 1998, 1999). Because I was impressed with the positive results of Lord's teaching techniques, and the potential application of his methods to large and small PATRICIA A. BURROWES is Associate Professor in the Department of Biology at the University of Puerto Rico, San Juan, Puerto Rico 00931-3360; e-mail: pburrowe@upracd.upr.clu.edu.