summary_questions: Questions Summary of Moodle Grade Report

In Lightbridge-KS/moodleStats: Analysis of Moodle Quiz Report

Questions Summary of Moodle Grade Report

Description

Calculate questions summary and item analysis of Moodle Grade Report (See Details).

Usage

summary_questions(data, cor_method = c("pearson", "kendall", "spearman"))

Arguments

data	(GradesReport) A data frame of class "GradesReport"
cor_method	(Character) A character string indicating which correlation coefficient is to be used for calculating Discrimination_Index. Default is Pearson's correlation ("pearson"). Other types can be specified such as "kendall", or "spearman", can be abbreviated.

Details

summary_questions() calculate overall summary grouped by each questions of Moodle Grade Report, and return the result as a data frame. The data frame has a column "Questions" for questions number in the quiz. Other columns are the followings.

Basic summary statistic

• n: number of students who answered each questions.

• min: student's minimum score of each questions.

• max: student's maximum score of each questions.

• max_setting: maximum score possible of each questions (from the quiz setting).

• mean: mean score of each questions.

• SD: standard deviation of each questions score.

Item analysis

• Difficulty_Index: Item Difficulty Index (p) is a measure of the proportion of examinees who answered the item correctly. It ranges between 0.0 and 1.0, higher value indicate lower question difficulty, and vice versa.

• Discrimination_Index: Item Discrimination Index (r) is a measure of how well an item is able to distinguish between examinees who are knowledgeable and those who are not. It is a pairwise point-biserial correlation between the score of each questions ("Q" columns) and total score of the quiz ("Grade" column). It range between -1.0 to 1.0. Negative values suggest a problem, indicating that score of the particular question is negatively correlated with total quiz score; therefore, revision of the question is suggested.

• p.value: A level of significant (p-value) of Discrimination_Index.

• p.signif: A Symbol indicating level of significant of Discrimination_Index.

Value

a data frame of overall summary per questions

References

• How to interpret an item analysis

See Also

• summary_quiz() for quiz summary statistics

• questions_stats() for question summary statistics with more parameters.

• item_discrim() for Item discrimination index with more parameters.

Examples

# Prepare
grades_df_preped <- prep_grades_report(grades_df)

# Question Summary
summary_questions(grades_df_preped)

Lightbridge-KS/moodleStats documentation built on April 7, 2022, 8:14 p.m.