angoff: Compute Angoff Coefficient

In JackStat/Lambda4: Collection of Internal Consistency Reliability Coefficients.

Description

Angoff's coefficient is most appropriately used for estimating reliability in tests that can be split into two parts with unequal lengths. The calculation corrects for the inequality of length in the splits. Angoff's coefficient is also believed to handle congeneric test structures relatively well.

Usage

  angoff(x, split.method = "even.odd",
    missing = "complete", standardize = FALSE)

Arguments

x	Can be either a data matrix or a covariance matrix
split.method	Specify method for splitting items?
missing	How to handle missing values.
standardize	When TRUE Results are standardized by using the correlation matrix instead of the covariance matrix for computation.

Value

angoff	The estimate of reliability.
Split	The split half key used to calculate angoff's coefficient.

Author(s)

Tyler Hunt [e-mail]

References

Feldt, L. S., & Charter, R. A. (2003). Estimating the reliability of a test split into two parts of equal or unequal length. Psychological Methods, 8(1), 102-109.

Sedere, M. U. And Feldt, L. S. (1977), The Sampling Distributions Of The Kristof Reliability Coefficient, The Feldt Coefficient, And Guttman's Lambda-2. Journal Of Educational Measurement, 14: 53-62.

Feldt, L. S. (1975). Estimation of the reliability of a test divided into two parts of unequal length. Psychometrika, 40, 557-561.

Angoff, W. H. (1953). Test reliability and effective test length. Psychometrika, 18, 1-14.

Examples

angoff(Rosenberg, split.method="even.odd", missing="complete", standardize=FALSE)

JackStat/Lambda4 documentation built on May 7, 2019, 10:16 a.m.