Estimating the number of subjects needed for a thinking aloud test
J Nielsen - International journal of human-computer studies, 1994 - Elsevier
Two studies of using the thinking aloud method for user interface testing showed that
experimenters who were not usability specialists could use the method. However, they found
only 28-30% of known usability problems when running a single test subject. Running more
test subjects increased the number of problems found, but with progressively diminishing
returns; after five test subjects 77-85% of the problems had been found.
experimenters who were not usability specialists could use the method. However, they found
only 28-30% of known usability problems when running a single test subject. Running more
test subjects increased the number of problems found, but with progressively diminishing
returns; after five test subjects 77-85% of the problems had been found.
