# Progress on generating educational questions from ontologies

With increasing student numbers, but not as much more funding for schools and universities, and the desire to automate certain tasks anyhow, there have been multiple efforts to generate and mark educational exercises automatically. There are a number of efforts for the relatively easy tasks, such as for learning a language, which range from the entry level with simple vocabulary exercises to advanced ones of automatically marking essays. I’ve dabbled in that area as well, mainly with 3rd-year capstone projects and 4th-year honours project student projects [1]. Then there’s one notch up with fact recall and concept meaning recall questions, and further steps up, such as generating multiple-choice questions (MCQs) with not just obviously wrong distractors but good distractors to make the question harder. There’s quite a bit of work done on generating those MCQs in theory and in tooling, notably [2,3,4,5]. As a recent review [6] also notes, however, there are still quite a few gaps. Among others, about generalisability of theory and systems – can you plug in any structured data or knowledge source to question templates – and the type of questions. Most of the research on ‘not-so-hard to generate and mark’ questions has been done for MCQs, but there are multiple of other types of questions that also should be doable to generate automatically, such as true/false, yes/no, and enumerations. For instance, with an axiom such as $impala \sqsubseteq \exists livesOn.land$ in a ontology or knowledge graph, a suitable question generation system may then generate “Does an impala live on land?” or “True or false: An impala lives on land.”, among other options.

We set out to make a start with tackling those sort of questions, for the type-level information from an ontology (cf. facts in the ABox or knowledge graph). The only work done there, when we started with it, was for the slick and fancy Inquire Biology [5], but which did not have their tech available for inspection and use, so we had to start from scratch. In particular, we wanted to find a way to be able to plug in any ontology into a system and generate those non-MCQ other types of educations questions (10 in total), where the questions generated are at least grammatically good and for which the answers also can be generated automatically, so that we get to automated marking as well.

Initial explorations started in 2019 with an honours project to develop some basics and a baseline, which was then expanded upon. Meanwhile, we have some more designed, developed, and evaluated, which was written up in the paper “Generating Answerable Questions from Ontologies for Educational Exercises” [7] that has been accepted for publication and presentation at the 15th international conference on metadata and semantics research (MTSR’21) that will be held online next week.

In short:

• Different types of questions and the answer they have to provide put different prerequisites on the content of the ontology with certain types of axioms. We specified those for 10 types of educational questions.
• Three strategies of question generation were devised, being ‘simple’ from the vocabulary and axioms and plug it into a template, guided by some more semantics in the ontology (a foundational ontology), and one that didn’t really care about either but rather took a natural language approach. Variants were added to cater for differences in naming and other variations, amounting to 75 question templates in total.
• The human evaluation with questions generated from three ontologies showed that while the semantics-based one was slightly better than the baseline, the NLP-based one gave the best results on syntactic and semantic correctness of the sentences (according to the human evaluators).
• It was tested with several ontologies in different domains, and the generalisability looks promising.

To be honest to those getting their hopes up: there are some issues that cause it never to make it to the ‘100% fabulous!’ if one still wants to designs a system that should be able to take any ontology as input. A main culprit is naming of elements in the ontology, which varies widely across ontologies. There are several guidelines for how to name entities, such as using camel case or underscores, and those things easily can be coded into an algorithm, indeed, but developers don’t stick to them consistently or there’s an ontology import that uses another naming convention so that there likely will be a glitch in the generated sentences here or there. Or they name things within the context of the hierarchy where they put the class, but in the question it is out of that context and then looks weird or is even meaningless. I moaned about this before; e.g., ‘American’ as the name of the class that should have been named ‘American Pizza’ in the Pizza ontology. Or the word used for the name of the class can have different POS tags such that it makes the generated sentence hard to read; e.g., ‘stuff’ as a noun or a verb.

Be this as it may, overall, promising results were obtained and are being extended (more to follow). Some details can be found in the (CRC of the) paper and the algorithms and data are available from the GitHub repo. The first author of the paper, Toky Raboanary, recently made a short presentation video about the paper for the yearly Open Evening/Showcase, which was held virtually and that page is still online available.

References

[1] Gilbert, N., Keet, C.M. Automating question generation and marking of language learning exercises for isiZulu. 6th International Workshop on Controlled Natural language (CNL’18). Davis, B., Keet, C.M., Wyner, A. (Eds.). IOS Press, FAIA vol. 304, 31-40. Co. Kildare, Ireland, 27-28 August 2018.

[2] Alsubait, T., Parsia, B., Sattler, U. Ontology-based multiple choice question generation. KI – Kuenstliche Intelligenz, 2016, 30(2), 183-188.

[3] Rodriguez Rocha, O., Faron Zucker, C. Automatic generation of quizzes from dbpedia according to educational standards. In: The Third Educational Knowledge Management Workshop. pp. 1035-1041 (2018), Lyon, France. April 23 – 27, 2018.

[4] Vega-Gorgojo, G. Clover Quiz: A trivia game powered by DBpedia. Semantic Web Journal, 2019, 10(4), 779-793.

[5] Chaudhri, V., Cheng, B., Overholtzer, A., Roschelle, J., Spaulding, A., Clark, P., Greaves, M., Gunning, D. Inquire biology: A textbook that answers questions. AI Magazine, 2013, 34(3), 55-72.

[6] Kurdi, G., Leo, J., Parsia, B., Sattler, U., Al-Emari, S. A systematic review of automatic question generation for educational purposes. Int. J. Artif. Intell. Edu, 2020, 30(1), 121-204.

[7] Raboanary, T., Wang, S., Keet, C.M. Generating Answerable Questions from Ontologies for Educational Exercises. 15th Metadata and Semantics Research Conference (MTSR’21). 29 Nov – 3 Dec, Madrid, Spain / online. Springer CCIS (in print).