A S L 3 Lecture Notes - Lecture 31: Internal Validity, Nuisance Variable, Planning Fallacy
Document Summary
A brief history of true experiments: to be considered an experiment a study must make use of a manipulation, manipulation occurs when an experimenter systematically alters the levels of a variable. True experiments eliminate individual differences: random assignment when combined with replication provides a powerful response to the problem of individual differences. True experiments allow researchers to observe the invisible. True experiments provide information about statistical interactions: semantic priming: the finding that people recognize most words more quickly than usual when they have just been exposed to words that have a similar meaning. The problem: artificiality: the lack of realism in experiments points to a potential artifact in all laboratory studies. The how-to s of laboratory studies: laboratory experiments can yield information that is impossible to obtain using any other research method. If a manipulation check would get in the way of the experimental task maybe a pilot test should be used to only document the effectiveness of the manipulation.
