Validity and Reliability in Research

Validity

• Validity refers to the extent to which an instrument measures what it's supposed to measure.

Content Validity

• Content validity assesses whether the individual items of a test represent what you want to assess.
• Face validity, a type of content validity, is determined by looking at the features of the instrument.
• Features like font size, spacing, paper size, and other elements that won't distract respondents while completing a questionnaire are considered.

Construct Validity

• Construct validity examines the extent to which a test measures a theoretical construct or concept.

Criterion-Related Validity

• Criterion-related validity assesses an instrument by comparing its scores to another criterion that measures the same trait or skill.
• Concurrent validity measures how well results align with established tests taken at the same time.
• Predictive validity measures the accuracy of predictions about future behavior.

Reliability

• Reliability refers to the consistency of measurements.
• A reliable test produces similar scores across various conditions and situations, including different evaluators and testing environments.

Test-Retest Reliability

• Test-retest reliability suggests subjects will achieve the same score when tested at different times.

Split-Half Reliability

• Split-half reliability, also known as internal consistency, indicates that a subject's scores on some trials consistently match their scores on other trials.
• A test is split into halves (e.g., odd and even numbered questions) and scores are compared to assess consistency.

Interrater Reliability

• Interrater reliability involves two independent raters observing and recording specified behaviors at the same time. This ensures consistency in scoring.
• This is often used to measure behaviors, like outbursts.

Alternate Forms Reliability

• Alternate forms reliability, also called parallel-forms reliability, is obtained by administering two equivalent tests to the same group of examinees.
• Items are matched for difficulty, and the time frame between administering each test is kept as short as possible to minimize extraneous variables impacting scores.

Explore the concepts of validity and reliability in research. Understand content, construct, and criterion-related validity. Learn how these principles ensure accurate and dependable research outcomes.