docs: Document student answers classification (#421)

* Document student answers classification

Signed-off-by: Yann Regis-Gianas <[email protected]>

* Apply suggestions from code review

Co-authored-by: Erik Martin-Dorel <[email protected]>

Author: yurug

docs/howto-classify-students-answers.md

@@ -0,0 +1,34 @@
+How to classify students answers
+================================
+
+## Context
+
+If you are a teacher with a large number of students, you probably
+want to get an idea of your students' typical answers to a given
+question without having to look at each of them individually.
+
+LearnOCaml provides an (experimental) feature to *automatically
+classify students answers*. From a given identifier, LearnOCaml
+computes the disimilarities between students' answers and regroup
+them in different clusters, so that the teacher can only look at
+one representant of each cluster to get a fairly comprehensive overview
+of students' ways to approach the assignment.
+
+## How-to
+
+Let's see how to analyze students' definitions of function `foo` in exercise `x`.
+Follow these steps:
+
+1. Go to the teaching tab in the LearnOCaml Web UI (needs a teacher token).
+
+2. Middle-click on the exercise `x` in the list of exercises.
+
+3. Enter `foo` in the dialog box.
+
+At this point, LearnOCaml opens a new window with the results.
+
+## References
+
+For more details about how this classification internally works, have
+a look at [asak](https://github.com/nobrakal/asak), a library to
+identify similar OCaml pieces of code.

docs/index.md

@@ -20,6 +20,7 @@ Howtos
 * [How to submit an exercise to the global corpus?](./howto-submit-an-exercise.md)
 * [How to deploy an instance of Learn OCaml?](./howto-deploy-a-learn-ocaml-instance.md)
 * [How to deploy Learn-OCaml statically?](./howto-deploy-learn-ocaml-statically.md)
+* [How to classify students answers?](./howto-classify-students-answers.md)
 
 Contacts
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