Development of online ultrasound instructional module and comparison to traditional teaching methods

Journal of Engineering Education, Jul 2002 by Nguyen, Jimmy, Paschal, Cynthia B

At this point the class was divided: the traditional, or control, half of the class began receiving standard classroom instruction along with lecture notes that lasted five 50-minute lecture periods over about a two week duration. Meanwhile, the remaining online, or experimental, half began using the device in the computer lab and continued on their own over the same duration. These students did not attend class and could access the device whenever and as often as they wanted. To ensure that the information given to both groups was identical except for presentation, lecture notes given to the traditional group were derived directly from the online tutorial.

An ultrasound homework was distributed electronically (as was norm for the course) two days after this first class period and was due after another week. An exam covering ultrasound material was given at the end of the instructional period, marking the end of the first rotation. Students were allowed and encouraged to work in groups on the homework and in studying for the exam, as was norm for the entire course, with an added restriction that they could work only with other members of their assigned group (traditional or online.) This was to maintain separation of instructional effects. It is unknown how strongly the students respected this restriction, though they were bound to it by the university's honor code.

The exam itself exam consisted of five questions, each having multiple parts. The first two questions focused on conceptual understanding and consisted of multiple choice and both short and intermediate length verbal questions (18 of 56 total points). The remaining three questions were computational in nature, requiring students to recognize relevant phenomena and make the appropriate calculations. The exam was conducted open book and open note, lasted 50 minutes, and was graded by the instructor in a blind fashion without knowledge of the students' identities. To maintain consistency, each problem was graded for the entire class before the stack of exams was shuffled and another one of the five problems was graded. The grading standards were quite rigorous with only excellent answers receiving the full point value. These grading procedures were standard for the entire course. To prevent instructional differences from affecting the grades of one group relative to those of the other, scores on this exam were scaled separately for each of the two groups around the mean score of the group. Therefore, no students were at a disadvantage. The scaled score counted towards each student's semester grade while the raw score was recorded for the purposes of the study.

After the exam concluded, students were asked to return completed time logs so that time spent by the groups could be compared.

A two-sample iota-test for independent samples at 95% confidence level was used, conditional to the equality of variances, for this and all other comparisons of means performed throughout the study.

On the next class period following the exam, post-test surveys were distributed in order to assess more subjective measures such as student satisfaction, level of interest generated, and positive and negative aspects of the teaching method that was experienced. The survey included both a multiple-choice portion phrased to express level of agreement with several statements and a free response portion welcoming general comments. After completing the survey, the study was complete and the second rotation began. The two study groups swapped places: the previous online group now attended a repeated session of lectures while the previous traditional group referred to the online device. This was done to maintain fairness; both groups were exposed to the same instruction and resources by the end of the semester and thus were presumably equally prepared for the final exam for the course.