# 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

 ```1 2``` ``` 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 [email protected]

## 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

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

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