The Spearman-Brown formula estimates test score reliability of a full-length test when using a split-half method of reliability.
The split-half method divides a test in two and calculate a correlation between the scores of the two halves. Longer tests are yield higher reliability values so the Spearman-Brown formula estimates the reliability value for the full test.
Other names for the Spearman-Brown formula are Spearman-Brown Prophecy Formula, Spearman-Brown Correction.
Learn more about test statistics in
Please check out my website www.suttong.com
Also, consider connecting with me on FACEBOOK Geoff W. Sutton
You can read many published articles at no charge: