Validity vs. Reliability
Validity:
Are you measuring what you need to measure?
It is an evaluation of the adequacy and appropriateness of the interpretations and uses of assessment results.
Are you measuring what you need to measure?
It is an evaluation of the adequacy and appropriateness of the interpretations and uses of assessment results.
Reliability:
(a) provides the consistency that makes validity possible
(b) indicates the degree to which various kinds of generalizations are justifiable.
- Refers to the consistency of measurement, that is, how consistent test scores or other assessment results are from one measurement to another.
(a) provides the consistency that makes validity possible
(b) indicates the degree to which various kinds of generalizations are justifiable.
- Refers to the consistency of measurement, that is, how consistent test scores or other assessment results are from one measurement to another.
The relation between reliability and validity can be confusing to someone who has encountered these terms for the first time. Reliability (consistency) of measurement is needed to obtain valid results, but we can have reliability without validity.
Examples:
Reliable and Valid: Having tested your students with with multiple things such as a test, group project, and lab on the anatomy of a cell. Your test has multiple and different ways of testing what they learned and you could compare their scores to check for reliability. If their results are consistent then you have reliable results.
Reliable and Valid: Having tested your students with with multiple things such as a test, group project, and lab on the anatomy of a cell. Your test has multiple and different ways of testing what they learned and you could compare their scores to check for reliability. If their results are consistent then you have reliable results.
Reliable but not Valid: You can use assessments and get consistent results, say 94%, 92%, 95% ect...however, you may not be measuring what you intended to measure. You can have a student read a passage from a short story or novel and then quiz them on it however, that is just memory, if you wanted them to analyze/understand the passage you could possibly be missing your mark. Thus having consistent reliable results but have no validity.
Not Reliable but Valid: Doesn't exist
Not Reliable and Not Valid: Using students' standardized test scores to measure teachers' abilities in the classroom, how well a school is doing, or student achievement is not valid and unreliable. It's Unreliable because there are too many factors, for example, students can be stressed because it is one of the biggest testes they will ever take and may not perform well. It's not valid because are the tests really measuring the teacher's ability or student achievement?
NOW YOU TRY! :)
Not Reliable but Valid: Doesn't exist
Not Reliable and Not Valid: Using students' standardized test scores to measure teachers' abilities in the classroom, how well a school is doing, or student achievement is not valid and unreliable. It's Unreliable because there are too many factors, for example, students can be stressed because it is one of the biggest testes they will ever take and may not perform well. It's not valid because are the tests really measuring the teacher's ability or student achievement?
NOW YOU TRY! :)