We are often asked if using different types of participants will affect the quality of data from online usability studies. For example, does a lab-based participant perform tasks the same way a participant from an online study does? Can we really trust data coming from online usability studies where participants might be getting involved just for the money?
These are all interesting points which were recently explored in a usability case study. The case study compared usability data from premium lab-based participants with cheaper online participants. The results were quite interesting. One might presume that the higher paid lab-based user would provide better quality data than their cheaper, online counterparts. However this was not the case. The results showed that satisfaction scores and completion rates obtained from the professional users were nearly identical and statistically indistinguishable to the lab-based users.
To read the full case study with analysis go here: www.measuringusability.com