Determination of the effectiveness of two methods for usability evaluation using a CPOE medication ordering system

► We determine the effectiveness of cognitive walkthrough (CW) and think aloud (TA). ► Effectiveness of TA is slightly better than that of CW in healthcare domain. ► CW and TA do not differ significantly in the number of identified problems. ► CW and TA do not differ significantly in the mean severity of usability problems. ► To uncover all usability problems a combination of methods is advised.