2.4.4 Reliability and Validity Flashcards
what is another word for reliability?
consistency
what does validity refer to?
legitimacy and accuracy of results
a study lacking reliability will also lack….
validity
what does internal reliability refer to?
how consistently the method measures within itself
in controlled research what needs to be standardised?
instructions, procedures, apparatus
in observations you can check for inter-rater reliability, what does this involve?
2 or more observers watching the same behaviour and comparing results
in questionnaires you need to make sure questions are unambiguous what does this mean?
interpreted in the same way by everyone
what are scales such as the likert scale? (strongly agree to disagree)
subjective, dependant upon interpretations
(internal reliability) when would final results be distorted, give an example:
when methods of measurement aren’t standardised
e.g. ruler consisting of variable centimetres
internal reliability can be checked by the split half method, what is this?
correlating results of half the items with the other half (odd numbers with evens on test) and gaining a high positive correlation coefficient
what does external reliability refer to? what should methods of measurement give?
how consistently a method measures over time when repeated
similar scores when repeated on same participants in similar conditions
give an example of when external reliability would be lacking:
if a ruler measured an object at different lengths each time it was used
external reliability can be checked by the test re-test method, what is this?
correlating results of the test conducted on one occasion with results of the test conducted on later occasion and gaining a high positive correlation coefficient
what does validity of a method of measurement refer to?
whether it measures what it is supposed to measure
what does internal validity refer to?
whether results were really due to the variables being measured