Answer Set

Answer Set is an Anki add-on which gives better feedback for "type in the answer" style cards if there are multiple correct answers and improves support for Indic scripts.

To install, open Anki and go to Tools > Add-ons in the menu bar, then click "Get Add-ons..." and enter this code: 1827331674

Multiple Answers

If you try to have multiple answers in a "type in the answer" style card in Anki, you will run into some issues. For instance, if you had "depart, go, leave" as the answer but typed "leave, go" instead, you would get:

This makes it difficult to see which answers you got correct, and which you actually did get wrong. With this add-on, the "correct" answers are rearranged before showing the difference, and so only this would be shown:

This is particularly useful for language learning, since often there will be multiple words matching a definition or multiple definitions for the same word.

Lenient Validation

This add-on also makes it possible to mark certain words in an answer as optional by putting them in parentheses or square brackets, or to accept any one of a set of words within an answer by separating them with slashes. See here for more details.

Improved Support for Indic Scripts

For some languages such as Tamil (தமிழ்), the script requires combining characters to represent vowels. Here is an example of the diff that Anki gives by default when typing "திரமபு" (tiramabu) instead of "திரும்பு" (tirumbu):

Separating the combining marks from the letters that they attach to make it difficult to see what is actually wrong, so this add-on groups combining marks before showing the difference:

Syntax

If the "correct" answer contains ;, then ; will separate the answer choices for rearranging. Otherwise, , will be used. This means that this:

a, b, c; d, e, f

Will be parsed into a, b, c as one answer and d, e, f as another. If you want to use different answer choice separators, you can configure them in the Anki add-on config page.

Config

There are a few special features which can be enabled/disabled in the add-on config in Anki:

• Lenient Validation
• Numeric Comparison
• Comments (Disabled by default)

Additionally, there is an "Equivalent Strings" config option to treat certain words as equivalent when checking answers. For instance, you may want to treat "I am" and "I'm" as being the same. To see all available options, open the add-on config page in Anki.

Implementation Details

This add-on is implemented as a monkey patch replacing Collection.compare_answer (Anki 2.1.56+) or Reviewer.correct (up to Anki 2.1.54), which are responsible for generating the differences. Since it replaces these functions, it is not guaranteed to work in future updates. I have tested it in Anki 2.1.40 through Anki 23.12.1.

The diffs between "given" and "correct" answer choices are rendered using a modified version of the Longest Common Subsequence, with a preference for grouping error regions together. It also has been modified to support "lenient validation", where brackets, text separated by slashes, and certain other characters are allowed to be missing from the given answer. Combining characters are grouped before finding the difference to improve support for non-ASCII text.

The answer rearranging algorithm uses the diff between "given" and "correct" answer choices to determine which correct answer is closest to which given answer for rearranging. The closest pair is grouped together first, then the next closest, and so on until there are no more pairs.

Changelog

2024-04-28:

• Use diff algorithm while matching answer choices to ensure best diff.

2024-03-18:

• Added config option to change answer choice separators.
• Improved handling of missing answer choice separators.

2024-03-17:

• Added numeric comparison config option.

2024-02-20:

• Use Unicode case folding for case-insensitive matching.
• Fixed Unicode normalization in config options.

2024-02-08:

• Added config option to treat certain strings as the same when comparing answers.

2024-01-21:

• Rewrote diff algorithm to handle lenient validation consistently.
• Added config option to ignore case when comparing answers.

2024-01-14:

• Fixed issue with finding differences for certain alternatives.

2024-01-08:

• Use new implementation for alternatives to fix issue.

2023-12-27:

• Fixed bug with alternatives in brackets next to other words.
• Allow whitespace in alternatives when inside of brackets.

2023-12-11:

• Added config option to ignore answer separators in brackets and parentheses.

2023-12-10:

• Changed choice-matching heuristic to maximize correct letters instead of minimizing wrong letters.

2023-11-29:

• Fixed issue with mixing alternatives with other lenient validation options.

2023-11-26:

• Added configuration options in Anki add-on config page.
• Comments are now disabled by default, but can be enabled in config.
• Lenient validation can now be disabled in config.
• Missing periods are now ignored by default, but this can be changed in config.

2023-11-15:

• Added support for optional text in brackets.
• Comments now must have a space immediately before them.

2023-07-13:

• Added support for alternatives separated by slashes.

2023-06-15:

• Fixed handling of HTML tags in expected answer.

Bugs

If you find a bug, please open an issue in this repository describing the issue.