stanine: Stanine Scores

In exametrika: Test Theory Analysis and Biclustering

Stanine Scores

Description

The Stanine (Standard Nine) scoring system divides students into nine groups based on a normalized distribution. This function is applicable only to binary response data.

These groups correspond to the following percentile ranges:

• Stanine 1: lowest 4% (percentiles 1-4)

• Stanine 2: next 7% (percentiles 5-11)

• Stanine 3: next 12% (percentiles 12-23)

• Stanine 4: next 17% (percentiles 24-40)

• Stanine 5: middle 20% (percentiles 41-60)

• Stanine 6: next 17% (percentiles 61-77)

• Stanine 7: next 12% (percentiles 78-89)

• Stanine 8: next 7% (percentiles 90-96)

• Stanine 9: highest 4% (percentiles 97-100)

Usage

stanine(U, na = NULL, Z = NULL, w = NULL)

## Default S3 method:
stanine(U, na = NULL, Z = NULL, w = NULL)

## S3 method for class 'binary'
stanine(U, na = NULL, Z = NULL, w = NULL)

Arguments

U	Either an object of class "exametrika" or raw data. When raw data is given, it is converted to the exametrika class with the dataFormat function.
na	Values to be treated as missing values.
Z	Missing indicator matrix of type matrix or data.frame. Values of 1 indicate observed responses, while 0 indicates missing data.
w	Item weight vector specifying the relative importance of each item.

Value

A list containing two elements:

stanine

The score boundaries for each stanine level

stanineScore

The stanine score (1-9) for each student

Note

This function is implemented using a binary data compatibility wrapper and will raise an error if used with polytomous data.

Stanine scores provide a normalized scale with:

• Mean = 5

• Standard deviation = 2

• Scores range from 1 to 9

• Score of 5 represents average performance

References

Angoff, W. H. (1984). Scales, norms, and equivalent scores. Educational Testing Service. (Reprint of chapter in R. L. Thorndike (Ed.) (1971) Educational Measurement (2nd Ed.). American Council on Education.

Examples

result <- stanine(J15S500)
# View score boundaries
result$stanine
# View individual scores
result$stanineScore

exametrika documentation built on Aug. 21, 2025, 5:27 p.m.