Ten nonphysical-science professors studied Newton's laws for a 3-week period along with 323 students in a noncalculus-based introductory physics course for science majors. The course contained innovations described in an earlier article [R. R. Hake, Am. J. Phys. 55, 878 (1987)]. Pre- and post-course mechanics exams indicated substantial increase in conceptual understanding for both professors and students over that obtained by students subjected to conventional instruction. The perspectives of the professorial peers on the innovations and various other aspects of the course are quoted at some length. Their major suggestions for instructional improvement of introductory physics courses are: (1) slow the pace at which topics are covered; (2) relate all educational activities to precisely stated course objectives; (3) devote some lecture time to setup and solution of problems with emphasis on models and strategy; (4) use a pedagogically advanced textbook; (5) relate abstract concepts to everyday concrete phenomena as achieved in demonstrations, "The Mechanical Universe" videotapes, and labs of the Socratic dialogue-inducing (SDI) type; (6) teach the course with much smaller lecture sections and with greatly increased faculty-student interaction.