2018 ASEE Annual Conference & Exposition

Problem Design in Homework

Engineering Mechanics—Dynamics is a required course for most engineering students. Almost all of the concepts and laws in this course have been introduced in General Physics. Therefore, the emphasis of this course is on the methods in solving problems. However, the solution manual for the textbook written by Russell Hibbeler can be downloaded from internet, and thus many students just copy the solution without trying to solve the problems with the new methods learned in this course.

In order to address this issue, the students in this class were divided into groups, and they were asked to redesign the problems in turns, and then the revised problems were assigned to the whole class. In spring 2017 semester, fourteen students registered for this course, and they were divided into four design groups. For each homework assignment, a design group was selected to redesign the problems in the textbook. The revised problems were reviewed by the instructor first, and then they were assigned to the whole class. At the end of the semester, students were surveyed on the following question: “Is it helpful for your study in working on the designed problems rather than the original ones?” Thirteen students participated in the survey, and the answer was very diverse: five positive, three equivocal, four negative, and one without answer.

There is an additional benefit in problem design. Physics laws can be considered as relationships between different parameters. The homework problems provide some parameters, and students are asked to figure out the missing parameters. For example, if X, Y, and Z are known, find W. In the redesign process, this problem can be revised in this way: if W, X, and Y are known, find Z. Therefore, the activity of problem design can help students realize the connections between these parameters. During the survey at the end of the semester, students were also asked the following question: “Do you feel empowered in designing the homework problems?” There is almost an even split: seven positive and six negative.
The effectiveness of teaching with this approach was assessed with the Mechanics Baseline Test, which has 26 multiple choice questions. The average score of the pre-test at the beginning of the semester was 15.0, and that of the post-test at the end of the semester was 19.4. On average, four more questions were answered correctly, which indicated a significant progress in learning this course.