Observe data collection at the moment of measurement See, observe, learn how data are collected at moment and place of measurement. "You never learn more about a process than when you directly observe how data are actually measured," said Cuthbert Daniel, a superb applied statistician. See with fresh eyes. Walk around what you want to learn about. Talk to those who do measurements. See how numbers came to be. Do those measuring know the desired answer? Are those measuring skilled, alert, honest, biased, incompetent, sloppy, tired and emotional?...Artifacts and errors in measurements measured? How are outliers adjudicated? Edward Tufte, Seeing With Fresh Eyes uxmeasurement
Website Response Times An Article by Jakob Nielsen www.nngroup.com Users really care about speed in interaction design...A snappy user experience beats a glamorous one, for the simple reason that people engage more with a site when they can move freely and focus on the content instead of on their endless wait. 0.1 seconds gives the feeling of instantaneous response. This level of responsiveness is essential to support the feeling of direct manipulation. 1 second keeps the user's flow of thought seamless. 10 seconds keeps the user's attention. A 10-second delay will often make users leave a site immediately. uxperformanceinteraction