E1929 Visualizations for Instructors
Introduction
Expertiza is an online assignment grading platform. Instructors can create assignments and implement peer reviews for submitted assignments. This project concerns the creation of a system for visualizing student performance on those assignments, primarily as graded in peer reviews. Graphs will be made to show various rubric criteria and the class' performance on the criteria. If the criteria are the same for multiple stages of review, an instructor should be able to compare performance over time or between reviews. Our task is to provide an interactive visualization or a table for instructors that shows how their class performed on selected rubric criteria. Such feature would be immensely helpful for instructors as it would assist them to identify what they need to focus more attention on. For example, creating a graph showing the average scores for all or a certain subset of main rubric criteria (questionnaire). If the average score of the class on selected criteria (question) is low means the instructor can emphasize more on the learning materials related to it.
Proposed Changes
The visualizations will be implemented as either a single or stacked bar chart with a bar for each of the selected criteria to be observed. If a single bar, then the height of the bar will be the total class average, but a stacked bar chart may be better to show the percentage of the class that received each score.
1. On clicking Manage and then on assignments, following page appears.
2. Click on 'view score' icon of an assignment. The summary report page of the selected assignment comes up.
3. Following are mockup screens which we wish to create:
a) Instructor would select the round and rubric criteria of the assignment for which he/she wants to view the class performance.
b) The bar graph of the class performance for those criteria would be displayed.
Project Design
The changes made to the expertiza project will primarily include HTML/ERB changes to the view files to accommodate the added charts on the page and the necessary javascript to allow responsive design. Brief controller modifications will be made to facilitate database filtering to get the displayed data.
Design Flow
The flowchart representing graphical flow of an instructor visiting view scores under assignments is given below:
Tools and Design Choice
We have used the lightweight Google Charts library for displaying the chart data on the page, with standard HTML for all of the options and dropdowns for option selection. Google Charts was chosen because of its high compatibility, full option set, and comparable graphical quality to the rest of expertiza while keeping a small JS footprint, which should help prevent slow page responsiveness.
Visualization
The following graph shows the view of the 'view scores' page after the modifications. The instructor selects a subset of rubric criteria for which he/she wants to know how a class performed for a particular round. A bar graph of the average score of the class for that subset of criteria is displayed.
The above graph shows an average score of the class for 10 rubric criteria in Round 1 for assignment "OSS project/Writing assignment 2" selected by the instructor. A live demo with randomly generated data can be found on JSFiddle
Test Plan
The team plans to perform both automated tests, using the RSpec framework, and manual tests of the user interface (UI), using the app.
RSpec Framework Tests
The RSpec Testing Framework, automated testing, will be used to verify the Models of the Expertiza Rails Web application feature set. Since this feature is dealing with Visualizations (charts) that is intimately tied with an Active Record Models, we will seed the Testing Database with known data via RSpec. These changes will be automatically rolled-back once the testing is complete.
Capybara Tests
Another automated testing framework that will be used is Capybara. Capybara is an browser type test to simulate a user clicking through your site. We will use this testing framework to verify that our charting object is present on the page and contains the seeded data that we had loaded.
UI Tests
In addition to the automated tests above we will also perform manual testing of the newly added features to include:
- Chart is displaying correctly
- Bars are showing up where expected
- Bar annotations are showing the expected value
- Criteria labels are for the correct bar and displaying correct values
- Hover text is displaying the correct values
- Null values are not present on the chart
- Correct colors are used for the multi-round view
- Show Labels checkbox works as expected
- Round Criteria is displaying correctly
- Round dropdown menu shows all rounds for the assignment
- Selecting a round changes the criteria checkboxes
- All checkboxes are displayed with appropriate text
- Checkboxes correctly remove or add criterion bars to the chart
Files Involved
We have implemented a new partial file criteria_charts to the team_chart that display the bar graph with existing data collected by the grades controller methods to the view page.
Modified files:
app/controllers/grades_controller.rb app/views/grades/_teams.html.erb app/views/grades/_criteria_charts.html.erb app/views/grades/_team_charts.html.erb
app/views/grades/_criteria_charts.html.erb
<html>
<head>
<%= content_tag :div, class: "chartdata_information", data: {chartdata: @chartdata} do %>
<% end %>
<%= content_tag :div, class: "text_information", data: {text: @text} do %>
<% end %>
<%= content_tag :div, class: "minmax_information", data: {minmax: @minmax} do %>
<% end %>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load('current', {packages: ['corechart', 'bar']});
//Display Options
var showLabels = true;
var barColors = [ // Other colors generated from the expertiza base red
'#A90201', // using paletton.com
'#018701',
'#016565',
'#A94D01'
];
function getData(){ //Loads all chart data from the page
chartData = $('.chartdata_information').data('chartdata');
chartText = $('.text_information').data('text');
chartRange = $('.minmax_information').data('minmax');
for (var i = 0; i < chartData.length; i++){ //Set all the criteriaSelected to true
var criteria = [];
for (var j = 0; j < chartData[i].length; j++){
criteria.push(true);
}
criteriaSelected.push(criteria);
}
}
function generateData() { //Generates random data for testing
var rounds = 3;
for(var i = 0; i < rounds; i++) {
var criteriaNum = Math.floor(Math.random() * 5 + 5); //Random number of criteria
var round = [];
var criteria = [];
for(var j = 0; j < criteriaNum; j++) {
round.push(Math.floor(Math.random() * 101)); //Random score for each criterion
criteria.push(true); //Everything starts out true
}
chartData.push(round);
criteriaSelected.push(criteria);
chartOptions = { //Render options for the chart
title: 'Class Average on Criteria',
titleTextStyle: {
fontName: 'arial',
fontSize: 18,
italic: false,
bold: true
chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
var checkBox = document.getElementById("labelCheck");
checkBox.checked = true;
checkBox.style.display = "inline";
updateChart(currentRound);
loadRounds(); }
function updateChart(roundNum) { //Updates the chart with a new round number and renders
currentRound = roundNum;
renderChart();
loadCriteria();
function renderChart() { //Renders the chart if changes have been made
var data = loadData();
chartOptions.vAxis.viewWindow.max = 5;
chartOptions.vAxis.viewWindow.min = 0;
if (chartRange[currentRound]) { //Set axis ranges if they exist
if (chartRange[currentRound][1])
chartOptions.vAxis.viewWindow.max = chartRange[currentRound][1];
if (chartRange[currentRound][0])
chartOptions.vAxis.viewWindow.min = chartRange[currentRound][0];
}
chart.draw(data, chartOptions);
}
chartOptions.hAxis.ticks = [];
var rowCount = 1;
for(var i = 0; i < chartData[currentRound].length; i++) { //Add a chart row for each criterion if not null
if (criteriaSelected[currentRound][i] && chartData[currentRound][i]) {
data.addRow([rowCount, chartData[currentRound][i], barColors[0], (showLabels) ? chartData[currentRound][i].toFixed(1).toString() : ""]);
chartOptions.hAxis.ticks.push({v: rowCount++, f: (i+1).toString()});
}
}
var data = new google.visualization.DataTable();
data.addColumn('number', 'Criterion');
var i;
for(i = 0; i < roundNum; i++) { //Add all columns for the data
data.addColumn('number', 'Round ' + (i+1).toString());
data.addColumn({type: 'string', role: 'style'}); //column for specifying the bar color
data.addColumn({type: 'string', role: 'annotation'});
var newRow = [];
var elementsAdded = false;
newRow.push(rowCount);
for(var j = 0; j < roundNum; j++) { //If the round has the criterion, add it
if (chartData[j][i]) {
newRow.push(chartData[j][i]);
elementsAdded = true;
} else {
newRow.push(null);
}
newRow.push(barColors[j % barColors.length]); //Add column color
if (chartData[j] && chartData[j][i] && showLabels)
newRow.push(chartData[j][i].toFixed(1).toString()); //Add column annotations
else
newRow.push("");
}
function loadCriteria() { //Creates the criteria check boxes
var form = document.getElementById("chartCriteria");
while (form.firstChild) //Clear out the old check boxes
form.removeChild(form.firstChild);
if (currentRound == -1) //Don't show criteria for 'all rounds'
return;
chartData[currentRound].forEach(function(dat, i) {
var checkbox = document.createElement('input');
checkbox.type = "checkbox";
checkbox.id = "checkboxoption" + i;
checkbox.onclick = function() { //Register callback to toggle the criterion
checkboxUpdate(i);
}
var label = document.createElement('label')
<form id="chartOptions" name="chartOptions">
<select id="chartRounds" name="rounds"
onChange="updateChart(document.chartOptions.chartRounds.options[document.chartOptions.chartRounds.options.selectedIndex].value)" style = "display: none">
</select>
<label><input type="checkbox" id = "labelCheck" checked="checked" style="display: none" onclick="showLabels = !showLabels; renderChart();">Show
Labels</label>
</form>
app/controllers/grades_controller.rb
def action_allowed?
case params[:action]
when 'view_my_scores'
['Instructor',
'Teaching Assistant',
'Administrator',
'Super-Administrator',
'Student'].include? current_role_name and
are_needed_authorizations_present?(params[:id], "reader", "reviewer") and
check_self_review_status
when 'view_team'
if ['Student'].include? current_role_name # students can only see the head map for their own team
participant = AssignmentParticipant.find(params[:id])
session[:user].id == participant.user_id
else
true
end
else
['Instructor',
'Teaching Assistant',
'Administrator',
'Super-Administrator'].include? current_role_name
end
end
# collects the question text for display on the chart
# Added as part of E1859
def assign_chart_text
@text = []
(1..@assignment.num_review_rounds).to_a.each do |round|
question = @questions[('review' + round.to_s).to_sym]
@text[round - 1] = []
next if question.nil?
(0..(question.length - 1)).to_a.each do |q|
@text[round - 1][q] = question[q].txt
end
end
end
# find the maximum and minimum scores for each questionnaire round
# Added as part of E1859
def assign_minmax(questionnaires)
@minmax = []
questionnaires.each do |questionnaire|
next if questionnaire.symbol != :review
round = AssignmentQuestionnaire.where(assignment_id: @assignment.id, questionnaire_id: questionnaire.id).first.used_in_round
next if round.nil?
@minmax[round - 1] = []
@minmax[round - 1][0] = if !questionnaire.min_question_score.nil? and questionnaire.min_question_score < 0
questionnaire.min_question_score
else
0
end
@minmax[round - 1][1] = if !questionnaire.max_question_score.nil?
questionnaire.max_question_score
else
5
end
end
end
# this method collects and averages all the review scores across teams
# Added as part of E1859
def assign_chart_data
@rounds = @assignment.num_review_rounds
@chartdata = []
(1..@rounds).to_a.each do |round|
@teams = AssignmentTeam.where(parent_id: @assignment.id)
@teamids = []
@result = []
@responseids = []
@scoreviews = []
(0..(@teams.length - 1)).to_a.each do |t|
@teamids[t] = @teams[t].id
@result[t] = ResponseMap.find_by_sql ["SELECT id FROM response_maps
WHERE type = 'ReviewResponseMap' AND reviewee_id = ?", @teamids[t]]
@responseids[t] = []
@scoreviews[t] = []
(0..(@result[t].length - 1)).to_a.each do |r|
@responseids[t][r] = Response.find_by_sql ["SELECT id FROM responses
WHERE round = ? AND map_id = ?", round, @result[t][r]]
@scoreviews[t][r] = Answer.where(response_id: @responseids[t][r][0]) unless @responseids[t][r].empty?
end
end
@chartdata[round - 1] = []
# because the nth first elements could be nil
# iterate until a non-nil value is found or move to next round
t = 0
r = 0
t += 1 while @scoreviews[t].nil?
while t < @scoreviews.length and @scoreviews[t][r].nil?
if r < @scoreviews[t].length - 1
r += 1
else
def assign_chart_data
end
end
next if t >= @scoreviews.length
(0..(@scoreviews[t][r].length - 1)).to_a.each do |q|
sum = 0
counter = 0
def retrieve_questions(questionnaires)
questionnaires.each do |questionnaire|
round = AssignmentQuestionnaire.where(assignment_id: @assignment.id, questionnaire_id: questionnaire.id).first.used_in_round
questionnaire_symbol = if !round.nil?
(questionnaire.symbol.to_s + round.to_s).to_sym
else
questionnaire.symbol
end
@questions[questionnaire_symbol] = questionnaire.questions
end
end
def update
if format("%.2f", total_score) != params[:participant][:grade]
participant.update_attribute(:grade, params[:participant][:grade])
message = if participant.grade.nil?
"The computed score will be used for " + participant.user.name + "."
else
"A score of " + params[:participant][:grade] + "% has been saved for " + participant.user.name + "."
end
end
flash[:note] = message
redirect_to action: 'edit', id: params[:id]
app/views/grades/_team_charts.html.erb
<br> <br>
<%= render :partial => 'criteria_charts' %>
<br>
<a href="#" name='team-chartLink' onClick="toggleElement('team-chart', 'stats');return false;">Hide stats</a>
<br>
<TR style ="background-color: white;" class="team" id="team-chart">
<th>
<div class="circle" id="average-score">
</div>
Class Average
</th>
<TH COLSPAN="8">
<img src="<%= @average_chart %>" ><br>
Class Distribution
<br>
</th>
<TH WIDTH="9"> </th>
</TR>
<script type="text/javascript">
var myCircle = Circles.create({
id: 'average-score',
radius: 50,
value: <%= @avg_of_avg.to_i %>,
maxValue: 100,
width: 15,
text: '<%=@avg_of_avg.to_i%>',
colors: ['#FFEB99', '#FFCC00'],
duration: 700,
textClass: 'circles-final'
});
</script>
<style>
.circles-final{
font-size: 16px !important;
}
</style>
Test Results
The team ran both automated tests, using the RSpec framework, and manual tests of the user interface (UI), using the app. The automated tests helped to ensure that the basic functionality of the app still worked, while the UI tests ensured that the visualizations were correct.
RSpec Test Results
In order to ensure that our changes did not affect basic functionality of the app, we made sure that all tests that passed before our changes also passed after our changes. Add statistics on the tests before our changes and matching statistics after our changes.
UI Tests
To validate all functionality of the chart when adding new features or fixing old ones, the following criteria were tested manually for expected functionality:
- Chart is displaying correctly
- Bars are showing up where expected
- Bar annotations are showing the expected value
- Criteria labels are for the correct bar and displaying correct values
- Hover text is displaying the correct values
- Null values are not present on the chart
- Correct colors are used for the multi-round view
- Show Labels checkbox works as expected
- Round Criteria is displaying correctly
- Round dropdown menu shows all rounds for the assignment
- Selecting a round changes the criteria checkboxes
- All checkboxes are displayed with appropriate text
- Checkboxes correctly remove or add criterion bars to the chart