Instructor: Auto Grading Options, Regular Expressions

Regular Expressions (RegEx) are algorithms that can be used to machine grade short answer, fill in the blank, arithmetic, and significant figures questions. Learn how to create your own Regular Expressions at Compose: Create Your Own Regular Expressions. For help using a tool that produces Regular Expressions for you, see Generate: Use the RegEx Generator.

Note: Use of RegEx in D2L quizzes may require spot-checking and/or manual regrading. Please review the materials provided to determine if RegEx is a good fit for your course.

1. Compose: Create Your Own Regular Expressions

Review examples to learn common RegEx commands and their functions.

Detailed information and interactive exercises can be found in this self-paced tutorial

Example 1: Case Insensitive Command (?i)

Question: Natural carmine dye is made from the _________ insect.

RegEx: (?i)cochineal 

Accepted answer/s: Cochineal, cochineal, CoChInEaL

Example 2: Either Or Command | (Pipe)

Question: What sound does a cat make?

RegEx: Meow|Purr|Hiss

Accepted answer/s: Meow, Purr, or Hiss

Example 3: Replace any literal character . (Period)

Question: What three-letter "spooky" animal is associated with Halloween?

RegEx: .at

Accepted answer/s: Bat, Cat, or Rat 

Example 4: Define the Beginning and End of a Pattern ^ (Caret) and $ (Dollar)

Note: RegEx commands are greedy and will match any portion of a pattern, unless otherwise specified. For example, yes matches any answer with the word "yes" in it, e.g., yes, yes please, and my answer is yes.

Question: Magnetic resonance imaging is abbreviated as ______.

RegEx: ^MRI$

Accepted answer: MRI - only "MRI" with no additional characters or spaces would be scored correct.

Common Regular Expressions

Character Name Description Example
* Asterisk

 Matches the preceding character zero or more times.

 cat* matches ca, cat, or catttt
\ Backslash  Marks a metacharacter as literal.

 c\.t matches c.t but not cat

^ Caret  Starts the input string or pattern.

 ^cat matches cat, catnip, but not tomcat

$ Dollar  Ends the input string or pattern.

 cat$ matches cat, tomcat, but not catnip. ^cat$ matches only cat

(?i) NA  Makes the pattern case insensitive.

(?i)cat matches CAT, cat, or CaT

( )  Parentheses

 Creates a subexpression.

 wild(cat)* matches wild or wildcat
. Period

 Matches any literal character.

 .at matches cat, bat, or rat
| Pipe

 Matches either or.

 cat|dog matches cat or dog.

D2L Brightspace Documentation: Understanding Regular Expressions


2. Generate: Use the RegEx Generator

Open the RegEx Generator and use its templates to produce custom Regular Expressions.


  • Multiple Correct Answers: use for multiple answers
  • Multiple Separators: use when words in an answer might be separated by spaces, dashes, slashes, or any single character
  • Multiple Suffixes: use when answers may have different endings
  • Diacritics: use when answers may contain diacritical marks

How to Use the Tool:

RegEx Generator templates appear as tabs in the upper-left corner of the browser window. All of the templates operate similarly. Any specific instructions for usage can be found in the tab, itself. 

  1. Begin by deciding whether accepted answers will be case sensitive. Leave unchecked if answers are to be case insensitive, e.g., Cat and cat are correct.Shows where case sensitive option can be selected
  2. Enter correct answer/s. The number of input fields will expand as needed for the Multiple Correct Answers Template. 
  3. As you type correct answer/s, the RegEx will concurrently appear in the designated area, below. Shows where to enter answers and where the RegEx appears
  4. Check the RegEx in the Test area by entering correct and incorrect answers. Shows where testing area is located

Note: The RegEx Generator is an evolving tool. Check back often for updates and new templates.


3. Apply: Insert Regular Expressions into D2L Quizzes

Format correct answer choices with RegEx to score open-ended questions.

For help getting started with open-ended questions, see Instructor: Create Open-Ended Questions. To learn how to format correct answer choices for RegEx, continue below.

  1. After typing or pasting your question into the Question Text boxscroll to the answer blank. 

    Note: Answer blanks may appear differently according to the question type. 

    Shows location of answer blank
  2. Type the RegEx into the answer blank or paste the code generated from the RegEx Generator.

  3. For short answer question types, toggle the leading dropdown menu to Regular Expression (pictured). For fill in the blank questions, select the Regular Expression option from the Evaluation column. 

    Shows where to select RegEx

    Note: You must indicate that the supplied answer is a Regular Expression. If not, D2L will treat the code as the literal, correct answer. Double, triple check that you have selected Regular Expression.

    1. Save

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