When a course designed around cooperative, problem-centered instruction attracts learners with a wide range of experience in the topic, should learners be grouped heterogeneously or homogeneously in terms of their relative expertise? In this study, learners were randomly distributed between the two types of groups; learning gains, satisfaction,…

This article presents a quasi-experimental study comparing the impact of two technology-related teacher professional development (TTPD) designs, aimed at helping junior high school science and mathematics teachers design online activities using the rapidly growing set of online learning resources available on the Internet. The first TTPD design…