Assessing Virtual Laboratories in a Digital-Filter Design Course: An Experimental Study

One hundred thirty-three undergraduate students in a digital filter design course participated in an experimental study. Two independent variables which occurred in a virtual laboratory environment were studied: 1) instructional treatments (online text-only materials, online texts with illustrations, and online texts with simulations); and 2) prior Internet experience (high and low). Three dependent variables were measured: 1) a knowledge achievement test; 2) intention to use instructional treatments; and 3) interaction levels with instructional treatments. The experimental research design of the study was a 3 times 2 randomized posttest design. Multivariate analysis of variance (MANOVA) was used to analyze collected data. The main effects and the potential interaction of the two independent variables were examined. Results indicate that the presentation of waveform variations and the change of parameters in the course content renders significant higher learning outcomes than online text-only materials and online texts with illustrations (Lambda (8,248) = 0.637, p < 0.05).