He was assessed of having anterograde (loss of ability to make NEW memories) and retrograde (loss of ability to recall events PRIOR to the injury) amnesia.
Shows that there is short term and long term memory storage. Informs us that short term memories need to be transferred to long term storage to be able to be retrieved again.
Using different but similar participants in each condition. An effort is made to match the participants in any important characteristics that might be important to the study.
Participants themselves may affect results as they have different characteristics, such as intelligence, level of motivation, age, personality, skills.
Participants have certain expectations concerning the experiment. Actual communication, what the participant may have heard about the experiment, effect of the experimenter causes the participant to alter their behaviour to meet the expectations.
Accepting the alternative hypothesis when results were not significant and null hypothesis should have actually been retained. Level of significance was too lenient