Information that is collected by direct observation
There are two ways to assess validity; face validity & concurrent validity.
Face Validity includes looking at a test to decide if it APPEARS to measure what it CLAIMS to be measuring.
Concurrent validity includes comparing results to a test that is known to be valid.
Reliabilility is the measure of consistency.
A test has external validity when there are consistent results every time the test is repeated.
External reliability can be assessed using the Test-retest method. This involves getting the same participant to take the same test on two sepreate occasions. Then compare the results obtained both times.
Internal reliability is a feature of questionaires and interviews.
A test has internal reliability if the individual items within a test are consistent with each other.
Internal reliability can be assessed using the split-half method. This involves splitting test-items in two, to see if results are consitent over the two halves of the test.
