Face validity
Encyclopedia
Face validity is a property of a test intended to measure something. It is the validity
of a test at face value
. In other words, a test can be said to have face validity if it "looks like" it is going to measure what it is supposed to measure. For instance, if you prepare a test to measure whether students can perform multiplication, and the people you show it to all agree that it looks like a good test of multiplication ability, you have shown the face validity of your test.
Some people use the term face validity only to refer to the validity of observers who are not expert in testing methodologies. For instance, if you have a test that is designed to measure whether children are good spellers, and you ask their parents whether the test is a good test, you are studying the face validity of the test. If you ask an expert in testing spelling, some people would argue that you are not testing face validity. This distinction seems too careful for most applications. Generally face validity means that the test "looks like" it will work, as opposed to "has been shown to work".
Face validity is often contrasted with Content validity
.
Validity
In logic, argument is valid if and only if its conclusion is entailed by its premises, a formula is valid if and only if it is true under every interpretation, and an argument form is valid if and only if every argument of that logical form is valid....
of a test at face value
Face value
The Face value is the value of a coin, stamp or paper money, as printed on the coin, stamp or bill itself by the minting authority. While the face value usually refers to the true value of the coin, stamp or bill in question it can sometimes be largely symbolic, as is often the case with bullion...
. In other words, a test can be said to have face validity if it "looks like" it is going to measure what it is supposed to measure. For instance, if you prepare a test to measure whether students can perform multiplication, and the people you show it to all agree that it looks like a good test of multiplication ability, you have shown the face validity of your test.
Some people use the term face validity only to refer to the validity of observers who are not expert in testing methodologies. For instance, if you have a test that is designed to measure whether children are good spellers, and you ask their parents whether the test is a good test, you are studying the face validity of the test. If you ask an expert in testing spelling, some people would argue that you are not testing face validity. This distinction seems too careful for most applications. Generally face validity means that the test "looks like" it will work, as opposed to "has been shown to work".
Face validity is often contrasted with Content validity
Content validity
In psychometrics, content validity refers to the extent to which a measure represents all facets of a given social construct. For example, a depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension...
.