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EDITING: item_analysis_spec.rb

# frozen_string_literal: true

#
# Copyright (C) 2013 - present Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.

require_relative "item_analysis/common"
require_relative "common"

describe Quizzes::QuizStatistics::ItemAnalysis do
  let(:report_type) { "item_analysis" }

include_examples "Quizzes::QuizStatistics::Report"

before(:once) do
    simple_quiz_with_submissions(
      %w[T D F A],
      %w[T B T A], # 2 wrong
      %w[T D F A], # correct
      %w[F A T C], # 4 wrong
      %w[T D F B], # 1 wrong
      %w[T D F A], # correct
      %w[F D]      # 3 wrong
    )
  end

it "generates a csv" do
    quiz_statistics = @quiz.statistics_csv("item_analysis")
    qs = @quiz.active_quiz_questions
    csv = quiz_statistics.csv_attachment.open.read
    stats = CSV.parse(csv)
    expect(stats[0]).to eq ["Question Id", "Question Title", "Answered Student Count", "Top Student Count", "Middle Student Count", "Bottom Student Count", "Quiz Question Count", "Correct Student Count", "Wrong Student Count", "Correct Student Ratio", "Wrong Student Ratio", "Correct Top Student Count", "Correct Middle Student Count", "Correct Bottom Student Count", "Variance", "Standard Deviation", "Difficulty Index", "Alpha", "Point Biserial of Correct", "Point Biserial of Distractor 2", "Point Biserial of Distractor 3", "Point Biserial of Distractor 4"]
    expect(stats[1]).to eq [qs[0].id.to_s, "Question text", "6", "2", "2", "2", "4", "4", "2", "0.6666666666666666", "0.3333333333333333", "2", "2", "0", "0.22222222222222224", "0.4714045207910317", "0.6666666666666666", "0.7786666666666666", "0.8696263565463043", "-0.8696263565463043", nil, nil]
    expect(stats[2]).to eq [qs[1].id.to_s, "Question text", "6", "2", "2", "2", "4", "4", "2", "0.6666666666666666", "0.3333333333333333", "2", "1", "1", "0.22222222222222224", "0.4714045207910317", "0.6666666666666666", "0.7786666666666666", "0.6324555320336759", "-0.7", "-0.09999999999999999", nil]
    expect(stats[3]).to eq [qs[2].id.to_s, "Question text", "5", "2", "2", "1", "4", "3", "2", "0.6", "0.4", "2", "1", "0", "0.24000000000000005", "0.48989794855663565", "0.6", "0.7786666666666666", "0.8728715609439694", "-0.8728715609439694", nil, nil]
    expect(stats[4]).to eq [qs[3].id.to_s, "Question text", "5", "2", "2", "1", "4", "3", "2", "0.6", "0.4", "2", "1", "0", "0.24000000000000005", "0.48989794855663565", "0.6", "0.7786666666666666", "0.6000991981489792", "0.13363062095621223", "-0.8685990362153794", nil]
  end

it "generates" do
    qs = @quiz.active_quiz_questions
    stats = @quiz.current_statistics_for("item_analysis")
    items = stats.report.generate

item = items[0].with_indifferent_access
    point_biserials = item.delete(:point_biserials)
    precision = 0.0001

expect(item[:question_id]).to eq qs[0].id
    expect(item[:answered_student_count]).to eq 6
    expect(item[:top_student_count]).to eq 2
    expect(item[:middle_student_count]).to eq 2
    expect(item[:bottom_student_count]).to eq 2
    expect(item[:correct_student_count]).to eq 4
    expect(item[:incorrect_student_count]).to eq 2
    expect(item[:correct_student_ratio]).to be_within(precision).of(0.6666666666666666)
    expect(item[:incorrect_student_ratio]).to be_within(precision).of(0.3333333333333333)
    expect(item[:correct_top_student_count]).to eq 2
    expect(item[:correct_middle_student_count]).to eq 2
    expect(item[:correct_bottom_student_count]).to eq 0
    expect(item[:variance]).to be_within(precision).of(0.22222222222222224)
    expect(item[:stdev]).to be_within(precision).of(0.4714045207910317)
    expect(item[:difficulty_index]).to be_within(precision).of(0.6666666666666666)
    expect(item[:alpha]).to be_within(precision).of(0.7786666666666666)

answer_ids = stats.report.send(:summary_stats_for_quiz).sorted_items[0].answers

expect(point_biserials.length).to eq 2 # this is a true/false question

expect(point_biserials[0][:answer_id]).to eq answer_ids[0]
    expect(point_biserials[0][:point_biserial]).to be_within(precision).of(0.8696263565463043)
    expect(point_biserials[0][:correct]).to be true
    expect(point_biserials[0][:distractor]).to be false

expect(point_biserials[1][:answer_id]).to eq answer_ids[1]
    expect(point_biserials[1][:point_biserial]).to be_within(precision).of(-0.8696263565463043)
    expect(point_biserials[1][:correct]).to be false
    expect(point_biserials[1][:distractor]).to be true
  end
end

CANCEL

Name	Type	Size	Modified	Actions
↩ ..	DIR	—	—
📁 item_analysis/	DIR	—	2023-09-24 03:36
📄 common.rb	RB	1.3 KB	2023-09-24 03:36	EDIT
📄 item_analysis_spec.rb	RB	4.9 KB	2023-09-24 03:36	EDIT
📄 student_analysis_spec.rb	RB	26.1 KB	2023-09-24 03:36	EDIT