nielsen@bellcore.com (Jakob Nielsen) (01/16/91)
Most empirical studies and user testing seems to be done with a rather small number of test users. Indeed, I often recommend the use of small samples myself for practical usability engineering purposes. For some current research on the statistical characteristics of user testing and the effect of varying the number of test users, I need access to larger data sets with results from empirical tests of user interfaces. Let us say that "large" = 40 subjects in the HCI field, even though this is modest compared with other fields where one can easily find studies with thousands of test users. I am interested in both objective measurements (such as time or errors when completing some task) and/or subjective measurements (user preferences or heuristic evaluations). If you have such data sets and might be willing to let me look at them, I would be grateful for an email message. It does not really matter what systems you studied, and I can let you remain anonymous or give you credit as you like. -- Jakob Nielsen, Bellcore MRE-2P370, 445 South St, Morristown, NJ 07962-1910, USA email nielsen@bellcore.com, tel. +1-201-829-4731, fax +1-201-538-9093
nielsen@bellcore.com (Jakob Nielsen) (01/22/91)
I have received a rather small number of replies to my request for data from empirical user interface studies with 40 test users or more. Therefore, I am still interesting in hearing about any additional such studies. Several people told me that they originally had such data but that it was not longer available. Unfortunately, much data seems to be deleted after the publication of papers, Ph.D. theses and such, making it difficult to do the kind of meta-study I am planning. -- Jakob Nielsen, Bellcore MRE-2P370, 445 South St, Morristown, NJ 07962-1910, USA email nielsen@bellcore.com, tel. +1-201-829-4731, fax +1-201-538-9093