Brain capabilities , especially memory , depend on external factors before and during the process of learningmemorisation . Your test is good at measuring how much has one person managed to fit into their brain , but comparing that result with the result of other persons can be faulty . Memorizing historic events can be easier to some , but harder to others , just to give an example . You will be able to control the environment of the test , but not the conditions before , such as is he tired , is he having a cluttered day already , is he relaxed , etc . In terms of method , yeah , probably it ' s fine to use the 0 , 1 interval and the mean of 0 . 5 . I think the most important thing would be , though , to have them memorize sets of numbers or names . It ' s more abstract and does not require any preknowledge from the subject . Although some people use tricks to memorize , such as abbreviating , mind mapping , or just have excellent photographic memory .