MongoDB: How to represent a schema diagram in a thesis?

Question

I am currently writing a thesis and need to display the schema of my MongoDB in a diagram. I have found no resources about diagrams for document-based databases.

There are Entity Relationship Diagrams (ERD) for relational databases. What options do I have for MongoDB? I've noticed that a lot of blogs just display the raw JSON as their "diagram" but this isn't feasible in my thesis.

Here is a sample of one of my JSON structures:

//MultiChoiceQuestion
{
    "title": "How are you?",
    "valid_answers" : [
        {
            "_id" : ObjectID(xxxx),
            "title": "Great",
            "isCorrect": true,
        },
        {
            "_id" : ObjectID(yyyy),
            "title": "OK",
            "isCorrect": false,
        },
        {
            "_id" : ObjectID(zzzz),
            "title": "Bad",
            "isCorrect": false,
        }
    ],
    "user_responses" : [
        {
            "user": ObjectID(aaaa),
            "answer": ObjectID(xxxx)
        },
        {
            "user": ObjectID(bbbb),
            "answer": ObjectID(xxxx)
        },
        {
            "user": ObjectID(cccc),
            "answer": ObjectID(yyyy)
        }
    ]
}

//User
{
    "_id": ObjectID(aaaa),
    "name": "Person A"
}
//User
{
    "_id": ObjectID(bbbb),
    "name": "Person B"
}
//User
{
    "_id": ObjectID(cccc),
    "name": "Person C"
}

Could this be a possible diagram:

Answer 1

We found class diagrams to actually be one of the best ways to represent a mongo schema design.

It can capture most of the items that a document will have such as arrays, embedded objects and even references.

General guidelines we use to relate onto concepts to uml

Embed = Composition aggregation

Reference = Association class

If you're unfamiliar with the uml terminology then this is a decent intro.

UML intro from IBM site