"Validity is the main extent to which a concept, conclusion or measurement is well-founded and likely corresponds accurately to the real world."
The extent to which a research study measures what it intends to measure and the consistency of the measurements, respectively.
Definition of validity: This refers to the degree to which a test measures what it purports to measure. A valid test is one that measures what it is supposed to measure.
Types of validity: There are several types of validity, including content validity, criterion validity, and construct validity. Each type measures a different aspect of validity.
Content validity: This type of validity refers to the extent to which a test represents the content it is supposed to represent. Content validity is often used in educational research to ensure that a test measures what it is intended to measure.
Criterion validity: This type of validity refers to the extent to which a test correlates with a specific criterion or outcome. For example, a reading comprehension test may be validated against a student's actual reading comprehension level.
Construct validity: This type of validity refers to the extent to which a test measures a theoretical construct or concept. Construct validity is often used in educational research to measure complex concepts such as intelligence or creativity.
Definition of reliability: This refers to the degree to which a test produces consistent results when administered multiple times. A reliable test is one that produces consistent results across multiple administrations.
Types of reliability: There are several types of reliability, including test-retest reliability, inter-rater reliability, and internal consistency reliability. Each type measures a different aspect of reliability.
Test-retest reliability: This type of reliability refers to the consistency of a test over time. For example, a math test administered to a group of students should produce similar results if administered again several weeks later.
Inter-rater reliability: This type of reliability refers to the consistency of a test when scored by different raters or evaluators. For example, a writing test may be scored by two different graders to ensure consistency in evaluation.
Internal consistency reliability: This type of reliability refers to the consistency within a test. For example, items on a math test should consistently measure the same concept, and not introduce other concepts.
Validity and reliability in educational research: These concepts are essential in educational research as they ensure that tests and measures are accurate, reliable, and produce consistent results. They ensure that the results of the research hold up over time and can be used as a basis for decision making.
Content Validity: The extent to which a test measures what it is intended to measure within a particular content domain.
Construct Validity: The extent to which a test measures an abstract concept or construct.
Face Validity: The degree to which a test appears to measure what it is intended to measure.
Criterion-Related Validity: The accuracy of a measure in predicting an outcome or criterion.
Concurrent Validity: The extent to which a test measures a particular construct at the same time as a previously established measure of that same construct.
Predictive Validity: The extent to which a test can predict a future outcome or criterion.
Ecological Validity: The extent to which the research findings can be generalized to the real-world or to other settings.
Test-Retest Reliability: The level of agreement or consistency of a measure over time, usually a test is administered twice to the same group of people.
Alternate Forms Reliability: The level of agreement between two different but equivalent forms of the same measure.
Internal Consistency Reliability: The degree of consistency between the items in a test that should measure the same construct or concept.
Interrater or Inter-Observer Reliability: The level of agreement among multiple raters or observers who score or evaluate the same measure.
Intrarater or Intra-Observer Reliability: The level of agreement between the scores given by the same rater or observer on different occasions.
Parallel Forms Reliability: The level of agreement or consistency between two different yet parallel versions of the same measure.
Equivalence Reliability: The level of agreement or consistency between two versions of the same test that measures the same construct in two different languages, cultures or formats.
"The word 'valid' is derived from the Latin validus, meaning strong."
"The validity of a measurement tool is the degree to which the tool measures what it claims to measure."
"Validity is based on the strength of a collection of different types of evidence (e.g. face validity, construct validity, etc.) described in greater detail below."
"In psychometrics, validity has a particular application known as test validity: 'the degree to which evidence and theory support the interpretations of test scores' ('as entailed by proposed uses of tests')."
"It is generally accepted that the concept of scientific validity addresses the nature of reality in terms of statistical measures and as such is an epistemological and philosophical issue as well as a question of measurement."
"The use of the term in logic is narrower, relating to the relationship between the premises and conclusion of an argument. In logic, validity refers to the property of an argument whereby if the premises are true then the truth of the conclusion follows by necessity."
"By contrast, 'scientific or statistical validity' is not a deductive claim that is necessarily truth-preserving, but is an inductive claim that remains true or false in an undecided manner."
"This is why 'scientific or statistical validity' is a claim that is qualified as being either strong or weak in its nature, it is never necessary nor certainly true."
"Validity is important because it can help determine what types of tests to use, and help to make sure researchers are using methods that are not only ethical, and cost-effective, but also a method that truly measures the idea or constructs in question."