From observation-based effective schools research, five essential correlates have been identified: (1) purpose; (2) measurement; (3) leadership; (4) expectations; and (5) climate. This paper briefly describes all correlates and then focuses on climate and expectations as applied to improving science instruction. Although climate originally referred to the physical comforts of a school or classroom, it came to denote the psychological environment--an environment conducive to learning. This concept can be further expanded by adding a planning dimension, including organization and management. Organization refers to things a teacher does (curriculum planning, activities, and strategies) before students are present. Management refers to things a teacher does (teaching and explaining and justifying classroom rules) after students have arrived. Both phases are essential and complementary. Hints are provided to ensure that classroom activities are satisfying and move along at a brisk pace. Sound instructional objectives and high teacher expectations are very important in science classes. Teachers must be careful not to discourage female students from pursuing an interest in science. There is a high correlation between attitudes and achievement. Teachers should be concerned about students' misconceptions about scientific concepts and their attitudes toward science. The best hope for encouraging students to consider science careers is to make their classes interesting, challenging, and meaningful. Proper classroom management techniques get students off to a good start. Included are 15 references. (MLH)