validity and reliability in research methods

Validity is the extent to which an instrument, such as a survey or test, measures what it is intended to measure (also known as internal validity). Other possibilities are that the instructions are not clear enough to be followed exactly how the experiment's designers intended them to be.We are currently in the process of updating this chapter and we appreciate your patience whilst this is being completed.

Tests that result in vastly different data when different types of individuals are used in an experiment, for example, can indicate that there is too much variation in the equipment or tools the researchers are using. Well-designed tests should produce similar results regardless of who is performing them. This type of assessment provides insights into whether your experiment yields stable, consistent data when it is repeated multiple times externally, including at a later date. Test-retest reliability measures how well tests produce similar results over time. Reliability can be determined if standard operating procedures (SOPs) are used to manage the way research is conducted so it can be reproduced. External reliabilityĮxternal reliability indicates how consistent a type of measure is over a period of time or with different types of survey conditions, such as different individuals, and how successfully this can be generalized. Strong internal reliability increases the overall confidence that your data is accurate, consistent, and replicable. This technique, which is known as internal reliability, assesses whether elements that are supposed to produce the same results do so consistently. Many complex experiments include two or more components that are intended to measure the same type of data. This means that it is generally a good idea to use a combination of tests to create the most complete picture of the reliability of your data. External reliability, parallel forms reliability, or other assessment options may also be appropriate, depending on the nature of the research you are conducting.Įach of these reliability types looks at a different factor that may affect the outcome of your research. Each option can be used to help you determine the overall accuracy and consistency of your research. Test-retest reliability, internal reliability, and inter-rater reliability are among the most common types of reliability assessment.

Validity and reliability in research methods