Assessments

NOTE: Any time you edit or add an infoAssessment.json file on a local copy of PrairieLearn, you need to click the “Load from disk” button in the header so that the local PrairieLearn server reloads the changes.

Overview

Each assessment is a single directory in the assessments folder or any subfolder. Assessments may be nested in subdirectories of the assessments folder. The assessment directory must contain a single file called infoAssessment.json that describes the assessment and looks like:

{
  "uuid": "cef0cbf3-6458-4f13-a418-ee4d7e7505dd",
  "type": "Exam",
  "title": "Coordinates and Vectors",
  "set": "Quiz",
  "number": "2",
  "allowAccess": [],
  "zones": [],
  "comment": "You can add comments to JSON files using this property."
}

The assessment ID is the full path relative to assessments.

Assessment naming

Assessments are organized into sets (e.g., Homework, Quiz, Exam) and within each set the assessment has a number. Additionally, each assessment has a title. Depending on the context, assessments are referred to by either a short name or a long name. The format of these is:

  • Short name = Set Number (e.g., Quiz 2 in the above example).

  • Long name = Set Number: Title (e.g., Quiz 2: Coordinates and Vectors above).

You can select a set from the list of standardized assessment sets or create your own.

Assessment types

Each assessment has a type, as listed below. A randomized assessment is one where each student gets a different set of questions in a randomized order, while a non-randomized assessment shows all students the same list of questions in the same order. Broadly speaking, randomized assessments are designed for exams and non-randomized assessments are designed for homeworks.

Type Randomized Description
Homework No A gamified assessment that rewards repeated correct answers to questions.
Exam Yes An exam where students can grade their answers at any time, and retry questions for reduced points.

Changing question-order randomization

To make Homework assessments randomize the question order for each student, set the "shuffleQuestions": true option in the infoAssessment.json file. This will use a unique-per-course number for each question, so that all students will still get the same question numbers (like #427), but they will not be in order. This makes it easy for students to discuss questions with course staff; they can say “I don't know how to do #427” and everyone will be seeing the same question #427. The main advantage of randomizing question order on Homeworks is to enable data collection on question difficulty and student behavior that is independent of the order in which questions are listed on the assessment.

There is currently no way to disable question order randomization for Exam assessments. However, the order of zones is fixed (see below), which can be used to control question order.

Question specification

An assessment is broken down in to a list of zones, like this:

"zones": [
    {
        "title": "Easy questions",
        "comment": "These are new questions created for this exam",
        "questions": [
            {"id": "anEasyQ", "points": [10, 5, 3, 1, 0.5, 0.25]},
            {"id": "aSlightlyHarderQ", "points": [10, 9, 7, 5]}
        ]
    },
    {
        "title": "Hard questions",
        "comment": "These are new questions created for this exam",
        "questions": [
            {"id": "hardQV1", "points": 10},
            {"id": "reallyHardQ", "points": [10, 10, 10]},
            {
                "numberChoose": 1,
                "points": 5,
                "alternatives": [
                    {"id": "FirstAltQ", "points": 10},
                    {"id": "SecondAltQ"}
                ]
            }
        ]
    }
],
  • Each zone appears in the given order in the assessment. Zone titles are optional and are displayed to the student if present.

  • Within each zone the question order is randomized for Exam assessments.

  • An assessment question can be specified by either a single id or by a list of alternatives, in which case one or more of these alternatives is chosen at random. Once the question id is determined, then a random variant of that question is selected. Question alternatives inherit the points of their parent group, if specified.

  • If a zone has maxPoints, then, of the points that are awarded for answering questions in this zone, at most maxPoints will count toward the total points.

  • If a zone has bestQuestions, then, of the questions in this zone, only bestQuestions with the highest number of awarded points will count toward the total points.

Assessment and question instances and resetting assessments

PrairieLearn distinguishes between assessments and assessment instances. An assessment is determined by the code in an assessments directory, and is something like "Midterm 1". Given an assessment, PrairieLearn needs to generate the random set of questions and question variants for each student, and it is this selection that is the assessment instance for the student. There is only one copy of each assessment, but every student has their own assessment instance. The rules for updating assessment instances differ between Homework and Exam assessments.

Exam assessment updates: Exam assessment instances are generated when the student starts the exam, and they are never automatically deleted, regenerated, or updated, even when the original assessment is changed in some way. This is a safety mechanism to avoid having students' assessments changed during an exam. However, if you want to force the regeneration of assessment instances then you can do so with the "reset" button on instructor view of the assessment. While writing an assessment you might need to do this many times. Once an assessment is live, you should of course be very careful about doing this (basically, don't do it on a production server once an assessment is underway).

Homework assessment updates: New questions added to Homeworks will be automatically integrated into student homeworks currently in progress. Updates to maxPoints or maxBonusPoints will take effect the next time a student grades a question. A student's "points" and "percentage score" will never decrease.

Assessment points

A student's percentage score will be determined by the number of points they have obtained, divided by the value of maxPoints (subject to the rules associated to credit in assessment access rules).

{
    "uuid": "cef0cbf3-6458-4f13-a418-ee4d7e7505dd",
    "maxPoints": 50,
    "maxBonusPoints": 5,
    ...
}

The maxPoints determines the number of points a student is required to obtain to get a score of 100%. The percentage score will thus be computed based on the points the student obtained divided by the value of maxPoints. If not provided, maxPoints is computed based on the maximum number of points that can be obtained from all questions in all zones.

By default, once a student obtains enough points to reach the value of maxPoints, any further points do not affect the assessment score. However, if a value is set for maxBonusPoints and credit is set to 100, the student can obtain additional points, up to a total of maxPoints + maxBonusPoints. The percentage is still based on maxPoints, so the use of maxBonusPoints allows students to obtain a percentage above 100%. If maxBonusPoints is set, but maxPoints is not provided, then maxPoints will be computed by subtracting maxBonusPoints from the maximum number of points in all questions.

The choice of using maxBonusPoints or a credit value above 100 is based on instructor's choice. Additional points based on maxBonusPoints are intended to be credited based on extra work, while credit above 100 is to be awarded for early completion. It is possible to combine them, and use them together in the same assessment. If maxBonusPoints is set while the credit is above 100, then the percentage is based on both maxBonusPoints and credit (see credit for details).

Multiple-instance versus single-instance assessments

By default all assessments are single instance, meaning that each student has exactly one instance of the assessment that they can complete, and once they have completed that assessment instance then they cannot do the assessment again. This is the expected behavior for homeworks, quizzes, exams, etc.

For practice exams it is often desirable to make a multiple instance assessment by setting the option "multipleInstance": true. This will allow students to create new assessment instances and try the whole assessment repeatedly.

Enabling group work for collaborative assessments

By default, assessment instances are tied to only one user. By setting groupWork: true, multiple students will be able to work on the same assessment instance. Information about the group configuration can be set in the infoAssessment.json file. For example:

{
  "groupWork": true,
  "groupMaxSize": 6,
  "groupMinSize": 2,
  "studentGroupCreate": true,
  "studentGroupJoin": true,
  "studentGroupLeave": true
}
Attribute Type Default Description
groupWork boolean false Enable the group work for the assessment.
groupMaxSize integer - The maximum size of a group (default: no minimum).
groupMinSize integer - The minimum size of a group (default: no maximum).
studentGroupCreate boolean false Allow students to create groups.
studentGroupJoin boolean false Allow students to join other groups by join code.
studentGroupLeave boolean false Allow students to leave groups.

Please notice: changing an assessment from group -> individual or vice versa after students have started working on it will cause student work to be lost.

Instructor options for groupWork

Instructor group assignment page

Underneath the "Groups" tab in an assessment, instructors have three ways of assigning students to different groups:

  1. Uploading a CSV file in the following format:
groupName,UID
groupA,one@example.com
groupA,two@example.com
groupB,three@example.com
groupB,four@example.com
  1. Automatically assigning students, either to fill out existing groups or to make entirely new ones.

  2. Copying the group assignments from another assessment.

A copy of the current group assignments can be saved from the "Downloads" tab, under <assessment>_group_configs.csv

Student options for groupWork

Student perspective for joining a group

If an instructor does not assign a student to a group, the student will need to join one before opening their assessment instance. They can either create a new one or join an existing group via a join code, which they can get from another classmate.

When calculating a student's grade for a group assessment, PrairieLearn will always use the score of their group's assessment instance.

Note: Students cannot see eachother's edits in real-time, although this is planned for a future version of PrairieLearn.

Student view of assessment with groupwork enabled

Students are able to see their groupmates' UIDs, which can become a point of contact to communicate with eachother outside of PrairieLearn. They are also able to leave their group to join a different one.

Auto-closing Exam assessments

By default Exam assessments will auto-close after six hours of inactivity by the student. This generally means that you don't need to explicity close exams that students accidentally did not close when they were done. If you want to prevent auto-closing then you can set "autoClose": false as a top-level option in the infoAssessment.json file.

Issue reporting

To allow students to report issues with questions (incorrect answers, unclear wording, etc), set the "allowIssueReporting": true property in the infoAssessment.json file, or set it to false to disallow reporting. This option defaults to true.

When issue reporting is allowed, students see a button labeled "Report an error in this question" and they can submit a short text form.

Report an issue button Describe the issue

Course staff see any reported issues show up on the "Issues" tab.

Issue report

Access control

See the Access control page for details.

By default, an assessment is only accessible to course staff. To allow students to access the assessment, the allowAccess option can be used in the assessment's infoAssessment.json file.

See the clientFiles and serverFiles page for details, and exam1 in the example course for an example.

Student-attached files

Students can attach files to assessments, either by uploading them or by pasting the file contents as text. This can be done on the assessment overview page, or on individual question pages. These files can be viewed by the student anytime they can view the assessment.

The purpose of this is to allow students to take extra notes during exams, for later review. For example, if a student has a Matlab script that they used to solve a question, they could attach it to that question so they can review it later.

This file attachment functionality does not provide a way for students to attach files before an exam starts, so it can't be used for student-provided "formula sheets" on exams.

Disabling real-time grading

PrairieLearn is designed to give students immediate feedback on their work. However, if you wish to more closely replicate a paper exam experience, you can prevent students from grading their work as they go (what we call "real-time grading").

Note that students generally expect and benefit from having immediate feedback, so this setting should only be enabled if you have a specific reason for it.

To disable real-time grading for an assessment, add "allowRealTimeGrading": false to the assessment's infoAssessment.json file. This will hide the "Save & Grade" button on student question pages; only the "Save" button will be available. The "Grade saved answers" button on the assessment overview will also be hidden. Note that real-time grading can only be disabled for Exam assessments, as immediate feedback is a core part of the Homework experience.

An assessment without real-time grading will not show any score information during the exam. However, if a time limit is used then when it runs out the assessment will auto-grade and show students exactly which questions they got correct/incorrect. The same revealing behavior will happen if an instructor manually closes and grades the student assessment. To prevent this, set the showClosedAssessment access rule restriction.

Disabling real-time grading changes a lot of fundamental details of how PrairieLearn is used. To account for that, the student assessment overview page displays less information about points and grading than for usual exams.

Here is the assessment page for a normal exam with real-time grading enabled:

Normal assessment

Here is the assessment page for an open exam with real-time grading disabled:

Open assessment with real-time grading disabled

Compared to the normal assessment, there are a number of differences:

  • A warning explaining that real-time grading has been disabled is shown
  • Total points is listed as a number, not as an "X/Y" score
  • The percentage bar is not displayed
  • The "Best submission" column is renamed to "Submission status"
  • The "Available points" column has been removed
  • The "Awarded points" column has been renamed to "Points" and only shows the max points

Here is the assessment page for a closed exam with real-time grading disabled:

Closed assessment with real-time grading disabled

Note that after the exam has closed and been graded, more information about points will be visible.

Limiting the number of attempts for each question

The number of times each student will be allowed to attempt each question can be set in different ways, depending on the type of question and assessment.

For assessments with type "Exam", each student will only be presented with a single variant of each question. The number of attempts will be determined by the points setting: if there is a single points value there will be a single attempt at the question; if points is set to a list of points, then there will be one attempt for each value in that list. In other words, the number of attempts is determined based on the number of values in the list of points.

For assessments with type "Homework", students will be presented with an unlimited number of attempts for each question. By default, every new attempt corresponds to a different variant of the question, unless:

  • the question is set to "singleVariant": true in the question configuration file. In this case, students will get unlimited attempts for the same variant.

  • the triesPerVariant setting is set as below. In this case, the student will have the set number of attempts to correctly answer the question. Once the student answers the question correctly, or the number of tries per variant is exhausted, the student will be given the option to try a new variant.

"zones": [
    {
        "questions": [
            {"id": "singleAttemptQ", "points": 10},
            {"id": "tryOncePerVar", "points": 10},
            {"id": "tryThreeTimesPerVar", "points": 10, "triesPerVariant": 3}
        ]
    }
],

Limiting the rate at which answers can be graded

Practice is important in learning and there should be room for mistakes and learning from them. Immediate feedback can help as it can give feedback despite the limited human resources. However, to prevent mindless trial-and-error problem solving, controlling resubmissions can be an effective tool (Ihantola et. al., Review of Recent Systems for Automatic Assessment of Programming Assignments).

One way to limit the amount of feedback provided to students is to limit the rate at which graded submissions are allowed. This can be done by using the gradeRateMinutes setting. If set, this value indicates how long a student needs to wait after grading a question to resubmit a new answer to the same question for grading. Students are still able to save a submission, but are not able to grade until either the waiting time has elapsed, or when they close the assesment. By default, this value is set to 0, which means that there is no limit.

The gradeRateMinutes value can be set for each specific question in the assessment. It can also be set for a zone or the full assessment, in which case it will apply individually to each question in the zone or assessment. In other words, if the assessment has a grading rate set, once a student submits an answer for grading in one question, they have to wait to submit new answers to that question, but they are able to grade other questions in the meantime.

"zones": [
    {
        "gradeRateMinutes": 30,
        "questions": [
            {"id": "canOnlySubmitEvery30minutes", "points": 10},
            {"id": "canOnlySubmitEvery60minutes", "points": 10, "gradeRateMinutes": 60},
            {"id": "canSubmitAnytime", "points": 10, "gradeRateMinutes": 0}
        ]
    }
],

Honor code

By default, Exam assessments require students to certify their identity and pledge an honor code before starting the assessment:

  • I certify that I am name and I am allowed to take this assessment.
  • I pledge on my honor that I will not give or receive any unauthorized assistance on this assessment and that all work will be my own.

To disable this requirement, set "requireHonorCode": false as a top-level option in the infoAssessment.json file.

The text of the honor code was based on the University of Maryland's Honor Pledge and the University of Rochester's Honor Pledge for Exams. This is a "modified" honor code (McCabe et al., 2002), as opposed to "traditional" codes that typically also require students to report any violations of the honor code they observe.

Linking to assessments

Some instructors may wish to publish links that point students directly to their assessments on PrairieLearn. These links may be published in course web pages, LMS systems like Compass or Canvas, or sent to students via email or other messaging platforms. Instructors should note that the URL listed on the browser points to the instructor view of an assessment, which is typically not accessible to students.

The appropriate link to provide to students can be found by opening the "Settings" tab of the Assessment. This page includes, among other useful information, a Student Link that can be provided to students. This link points students directly to the specific assessment, enrolling them automatically in the course if they are not yet enrolled.