A methodology has been developed and successfully implemented for transforming physical experiments in an undergraduate thermo-fluids laboratory at Old Dominion University (ODU), a doctoral university, into web-based virtual experiments while the Mechanical Engineering (ME) faculty at Western Kentucky University (WKU), an undergraduate university, have developed and implemented a Design of Experiments (DOE) Plan to assure that graduates of their program have acquired the skills necessary to design and conduct experiments and analyze experimental results. This paper presents details about a web-based virtual experiment designed to teach students about selection of instruments based on the uncertainty estimated from the virtual experiment. The web-based virtual experiment, involves the measurement of frictional losses in fluid flowing in a pipe at various flow rates. In this virtual module, the student experimenter can adjust the flow rate in the pipe with a virtual flow control valve and measure both the flow rate and the pressure drop by selecting different measuring instruments. The selected instruments have corresponding measurement uncertainties and the student is tasked through various activities in the virtual experiment to evaluate which instrument is the best fit for the particular experimental design situation. The web-based virtual module has been tested at ODU and an assessment of its effectiveness in student learning is provided. Student learning gains achieved through the web-based virtual module were measured by comparing the performance of a Control group (no access to the module) and an Experimental group with access to the web-based virtual module. Both groups were administered an identical multiple choice quiz and the quiz scores were analyzed to gage the effectiveness of the module in teaching students about instrument selection, and uncertainty and errors in experiments. Students in the Experimental group were also surveyed to get their feedback on the effectiveness of the module in aiding their learning of these skills
