Common spelling mistakes
hypothesis vs. hypotheses
Hypothesis is a singular noun (like mouse), hypotheses is a plural noun (like mice). One prediction about the way an experiment will turn out is a hypothesis. Several predictions are hypotheses.
stimulus vs. stimuli
Stimulus = singular (like mouse), stimuli = plural (like mice). One electric shock is an unpleasant stimulus. Electric shocks are unpleasant stimuli.
phenomenon vs. phenomena
Phenomenon = singular (like mouse), phenomena = plural (like mice). Lightning is a natural phenomenon. Thunder and lightning are natural phenomena.
criterion vs. criteria
Criterion = singular, criteria = plural (I think I see a pattern emerging!). Being 18 is a criterion for drinking alcohol. Being 21 and having a full driving license are criteria for getting a job as a bus driver.
cite vs. site
A site is a place or a location. This is the site of the battle of Waterloo. Cite is what you do when you quote or reference something. Milgram, 1953 (cited in Gleitman et al., 1999)...
affect vs. effect
This is a really tricky one. As a verb, affect (a-FECT) means "have an influence on". Lack of sleep affects test performance. As a noun, affect (AFF-ect) refers to feelings or emotions. Sadness is a negative affect.As a noun, effect means "influence". Lack of sleep has a bad effect on my mood. As a verb, effect means "create". Milgram effected a change in the way we think about obedience and authority.
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Last updated 20th October 2002