research methods

• When a study is replicated, and the results are not consistent, we say the study lacks reliability .
• Variables in the environment, other than what the researchers are manipulating, that might affect participant behaviour are called situational variables.
• In psychology, validity means that a test measures what it claims to be measuring.
• A study lacks validity if the method of measurement doesn’t measure what it claims to measure and also if there are extraneous or confounding variables that affect the measurement.
• Face validity and concurrent validity are ways of assessing validity.
• When assessing the face validity of a test, we look at the test to see if it appears to measure what it claims to measure.
• When assessing the concurrent validity of a test, we compare the results obtained to a previous test of the same behaviour, that is known to be valid.
• We say that studies are reliable when the results of the study are consistent every time it is repeated.
• A study can lack reliability if there are extraneous variables affecting the measurements, or if the test used to measure the dependent variable is unreliable.
• If the results of a study are inconsistent every time the study is repeated, we can say that the study lacks reliability.
• A study can lack reliability if there are extraneous variables affecting the measurements and also if the test or questionnaire used to measure the DV is itself unreliable.
• A test has internal reliability if the individual items within a questionnaire are consistent with each other.
• internal reliability is when the individual items within a test are consistent with each other.
•  external reliability is when the results of a test are consistent every time it is used.
• The split-half method tests internal reliability by splitting the test items in two and comparing the results.
• The test-retest method tests the external reliability of a questionnaire or test by getting the same participants to take the same questionnaire or test on two separate occasions and comparing the results.
• External reliability is when the results of a study are consistent every time it is repeated.
• A study can lack external reliability because there are extraneous variables affecting the dependent variable and also because the test or questionnaire lacks reliability.