An objects-first strategy for teaching introductory computer science courses is receiving increased attention from CS educators. In this paper, we discuss the challenge of the objects-first strategy and present a new approach that attempts to meet this challenge. The new approach is centered on the visualization of objects and their behaviors using a 3D animation environment. Statistical data as well as informal observations are summarized to show evidence of student performance as a result of this approach. A comparison is made of the pedagogical aspects of this new approach with that of other relevant work.

We study how the relative values placed on a variety of software design criteria differs between beginning students, advanced students, and educators. We also consider how these values change depending on the specific design situation. Statistical analysis of data collectedfrom over 300 subjects reveals relatively small differences between the two student populations and significant differences between educators and students. In addition to often valuing different criteria, educators also value criteria more consistently across the design situations.

This paper describes an approach for introducing recursion, as part of a course for novice programmers. The course is designed to make use of a 3-D animation world-builder as a visualization tool that allows students to see their own programs in action. One of the pedagogical goals of the course is to enable the student to gain an intuitive sense of and mathematical insight into the recursive process. The software, examples of animation using recursion, and some experiences in using this approach are discussed. What is Alice.'?Alice98 (www.alice.org) is a 3-D interactive graphics programming environment for Windows built by the Stage 3 Research Group at Carnegie Mellon University under the direction of Randy Pausch [15]. Alice offers a full scripting and prototyping environment for 3-D object behavior (e.g., animals