Editing Psychological statistics (section)

====Reliability ====
{{Main|Reliability (research methods)}}

The reliability is computed in specific ways.  
(A)	Inter-Rater reliability: Inter-Rater reliability is estimate of agreement between independent raters. This is most useful for subjective responses. [[Cohen's kappa|Cohen's Kappa]], [[Krippendorff's Alpha]], [[Intra-class correlation coefficient|Intra-Class correlation coefficients]], [[Correlation coefficient]]s, Kendal's concordance coefficient, etc. are useful statistical tools. 
(B)	Test-Retest Reliability: Test-Retest Procedure is estimation of temporal consistency of the test. A test is administered twice to the same sample with a time interval. Correlation between two sets of scores is used as an estimate of reliability. Testing conditions are assumed to be identical. 
(C)	 Internal Consistency Reliability: Internal consistency reliability estimates consistency of items with each other. Split-half reliability ([[Spearman–Brown prediction formula|Spearman- Brown Prophecy]]) and [[Cronbach's alpha|Cronbach Alpha]] are popular estimates of this reliability.<ref>Cronbach LJ (1951). Coefficient alpha and the internal structure of tests. Psychometrika 16, 297–334. doi:10.1007/bf02310555</ref> 
(D)	[[Parallel-forms Reliability|Parallel Form Reliability]]: It is an estimate of consistency between two different instruments of measurement. The inter-correlation between two parallel forms of a test or scale is used as an estimate of parallel form reliability.