CTTvis (version 0.1.1)

coefficient_alpha_plot: coefficient_alpha_visualization

Description

plotting results of coefficient alpha analysis from the Classical test theory framework. Items that increase the overall coefficient alpha when dropped will be shown above the overall alpha line. This helps identifying items that could be revised or removed based on its influence to unidimensional coefficient alpha reliability of the test.

This function can also be used with polytomous item responses. However, it is recommended for users to perform reverse coding as necessary before implementing this function.

Usage

coefficient_alpha_plot(responses, title = "Coefficient Alpha", alpha_round = 3)

Value

A data frame sorted by coefficient alpha if dropped in ascending order. A plot of coefficient alpha of each item in relation to the overall coefficient alpha.

Arguments

responses

A dichotompus item response object (a dataframe or a matrix)

title

Title of the plot

alpha_round

Rounding option for coefficient alpha. default to 4 decimal points.

Examples

data(reliability_df)

# To plot coefficient alpha with the overall alpha rounding of 3 decimal places

coefficient_alpha_plot(responses = reliability_df,
      title = "Coefficient Alpha Plot", alpha_round = 3)