Definition

Noun: A statistical measure of reliability, specifically the correlation coefficient calculated between the scores obtained on two halves (typically odd-numbered items versus even-numbered items) of a single test. This coefficient is used as an estimate of the test's internal consistency or reliability.

Usage

This term is used in the fields of psychometrics, educational testing, and psychological assessment. It describes a specific methodological step in evaluating how consistently a test measures a construct.

Examples

• The researcher calculated the chance-half correlation to estimate the reliability of the new personality inventory.
• A high chance-half correlation coefficient suggests that the two halves of the test are measuring the same underlying trait consistently.
• Before finalizing the exam, the professor checked its internal consistency by examining the chance-half correlation.

Advanced Usage

• The chance-half correlation is often adjusted using the Spearman-Brown prophecy formula to estimate the reliability of the full-length test.
• This method is a form of analysis, where "chance-half" refers to the random or systematic (e.g., odd-even) division of test items.

Variants and Related Words

• Split-half reliability (n): The broader concept of estimating reliability by correlating scores from two halves of a test. A chance-half correlation is one way to compute this.
• Internal consistency (n): The overall degree to which the items on a test measure the same concept; chance-half correlation is one measure of it.
• Reliability coefficient (n): A general term for any numerical index of a test's reliability, which includes the chance-half correlation.

Synonyms

• Split-half coefficient
• Odd-even correlation (when the split is specifically between odd and even numbered items)

Related Phrases/Concepts

• Spearman-Brown formula: A formula used to correct or adjust the chance-half correlation to estimate the reliability of the entire test.
• Test reliability: The consistency of a measuring test or experiment. The chance-half correlation is a method to assess it.

Noun

1. a correlation coefficient calculated between scores on two halves of a test; taken as an indication of the reliability of the test