Authoring questions

Examples

See some examples on this website https://examples.opentaproject.com/lti.

Content in OpenTA consists of exercises with one or many questions. An exercise and its questions are created using a custom XML format. For example,

example.xml

<exercise>
  <exercisename>Momentum and energy</exercisename>
  <global>
	m = 3 kg; v = 5 meter / second;
  </global>
  <text>
    A particle with mass $m$ is moving with velocity $v$.
  </text>
  <question key="1">
    <text>What is the energy of the particle?</text>
    <expression>m*v^2/2</expression>
  </question>
  <question key="2">
    <text>What is the momentum  of the particle?</text>
    <expression>m*v</expression>
  </question>
</exercise>

Mathematics typesetting

OpenTA supports typesetting mathematical expressions in text through KaTeX. This means that whenever you want to show some mathematics, for example $\frac{1+x^2}{\sqrt{1-x}}$, you write the corresponding LaTeX syntax within dollar signs: $frac{1+x^2}{sqrt{1-x}}$ .

See the LaTeX wiki for a syntax reference.

For some more hands-on examples see this stackexchange collection (this is aimed at MathJax which also uses the same syntax).

Here is the full xml schema !

Creating Exercises

Here are instructions for creating exercises

OPENTA XML Generation Rules

This section describes the rules for generating OPENTA-compatible XML exercises. You can copy the entire section and use it as an instruction in ChatGPT. Or you can get the textfile here which you can paste in as an instruction in chatgpt query. It is very incomplete but it might help.

chatgpt instruction:

When generating an exercise, the XML must follow the structure below:

<exercise>
    <exercisename>EXERCISE_NAME</exercisename>
    <global>var1 = value1; var2 = value2; ...</global>
    <text>TEXT EXPLAINING THE EXERCISE</text>

    <question key="RANDOMKEY1">
        <text>TEXT EXPLAINING THE QUESTION</text>
        <expression>A MATHEMATICAL EXPRESSION THAT IS THE CORRECT ANSWER TO THE QUESTION</expression>
    </question>
</exercise>

The values value1, value2 etc. may include units when relevant. Units must be written out in full, for example: meter, second, kg.

Example:

g = 9.800 meter / second^2

Since units are already included in the global variable definitions, student answers must not contain units. Expressions inside <expression> must refer only to variables.

Use at least four significant figures when assigning numerical values.
Avoid whole numbers and simple fractions.
Angles must always be expressed in radians.
The word radian must never be used in an expression.
Avoid special angles unless specifically requested.

Mathematical expressions inside <text> tags must be wrapped in dollar signs to ensure MathJax rendering.

Example:

<text>The vector has length $ \sqrt{x^2 + y^2} $.</text>

All variables appearing inside:

<expression> ... </expression>

must:

Be defined inside the <global> tag.
Have reasonable numerical values.
Include units when appropriate.

Hints may be added to enforce restrictions or requirements on student answers.

A hint block has the form:

<hint>
    <regex present="ATTRIBUTE">REGEX</regex>
    <comment>COMMENT</comment>
</hint>

The ATTRIBUTE can be one of:

required
forbidden
necessary
allowed
encouraged
discouraged

Hints may be placed inside the <global> tag or inside an individual <question> tag.

Use cases include:

forbidden – prohibit certain answer forms
required – demand that a specific structure appears
necessary – enforce a mandatory component
allowed – whitelist forms
encouraged / discouraged – guide style without strict enforcement

When including a regex, the system should remind the user that the above attributes are available.

If an exercise requires solving for multiple different variables:

Create one <question> element per variable.
Each question must have a unique key attribute.
Each question must include its own <text> and <expression>.

The <expression> tag contains only the target expression and must not contain an equal sign.

The <text> tag inside the question explains which variable the student is expected to compute.

XML SCHEMA

Here is the full xml schema

You can validate all the exercises in OpenTA by pressing “Validate Exercises” in the toolbar