AI for Teachers, An Open Textbook: Edition 1

AI Speak : How Adaptive Systems Learn the Learner Part 1

When looking at an adaptive learning system, it is very hard to tell where it adapts.1 What technology is used and what it is used for also changes across systems.

However, all adaptive learning systems know whom they teach (knowledge about the learner), what they teach (knowledge about the domain), and how to teach (knowledge about pedagogy).2

An ideal ALS adapts itself in multiple ways. In the outer loop, the sequence of learning activities is adapted - similar to Youtube adapting recommended list of videos. The outer loop might also personalise learning approaches and difficulty levels.

In the inner loop, within each activity, the ALS monitors step-by-step progress. It adapts feedback and hints to correct misconceptions, if any. It might also point to additional content if the student has a problem remembering a previously learnt concept. Some experts argue that the inner loop is best left to the instructor : not only is it costly and time consuming to program all the rules for the specific subject and task, but the teacher’s knowledge and experience will always trump the machine’s.3

How Adaptive Systems learn the learner

Like all recommendation problems ( See How Youtube Learns You Part 1), ALS splits the task into one or more surrogate questions that can be answered by the machine. Again, the choice of what to ask -and thus, what to predict, has a big impact on what recommendation is shown.

Marketing material often mention multiple goals : improved scores, employability, engagement.. Given the proprietary nature of the systems, it is usually unclear what questions are coded into the systems, what goals are being optimised for, and how short term goals are differentiated from long term goals (example, mastery of a given content to progressing to the next grade level.)4

Where machine learning is used, whatever be the goals chosen, the prediction itself is based on other learners with similar skill levels and preferences. That is, learners whose models are similar.

The Learner model

For creating a student model developers ask what student characteristics are relevant to the learning process. Unlike teachers who can directly observe their students and adjust their approach, machines are limited to the data that can be collected and processed by them.

Typical characteristics considered in a student model:While this data changes and has to be recorded and updated, models also contain static characteristics such as age, gender, mother tongue and email id.2

Most of the ALS create learner models based on the interactions with the students. Some also glean info from other sites, especially social media. Once a model is available for each learner, the machine calculates which students are similar to one another and estimate the probability that a given student will benefit from an activity, example or question.3
 

The Domain model

We can draw a loose parallel between learning objects in an ALS and videos in Youtube. A subject can be broken down into concepts and skills, called knowledge units (KUs) : these are what the learner needs to know.3 Each KU has a set of learning objects through which content can be learned and a set of activities to assess learning. Some authors further break down learning objects into learning activities, we do not do so here.

Learning objects  can be text to read, a video, a set of problems, interactive activities (from simple fill in the blanks to scenario based learning activities), interactive animation etc.1The learning objects give what the learner needs to know and the assessment activities indicate if the knowledge has been acquired.3The domain model contains all the features of the learning objects, including the associated KU and assesment.

What a learner learns next will also depend on the inter-relationships between the KUs and thus these need to go in to the model too : Learning objects A and B might both be pre-requisites for Learning object D. Thus, A and B have to be mastered before D. There is order amongst some KUs that tell us how we learn.3 Conversely, if the student solves correctly a problem that corresponds to D, it would be a good bet that he mastered A and B too.

Subject matter experts can provide some of these relationships. Rest of the inferences can be learnt by the machine that can predict the probability that a KU has been mastered: how sure a system is that the learner has mastered A and B, given that he answered questions under D. It can then use this information, along with other features of learner and domain models to recommend learning pathways and learning objects.
Other features of learning objects could include the difficulty level of the activity, its popularity and ratings. The goal here, like in the case of Youtube recommendation, is to squeeze out as much information as possible from the data available

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1 EdSurge, Decoding Adaptive, Pearson, London, 2016
2 Alkhatlan, A., Kalita, J.K., Intelligent Tutoring Systems: A Comprehensive Historical Survey with Recent Developments, International Journal of Computer Applications 181(43):1-20, March 2019
3 Essa, A., A possible future for next generation adaptive learning systems, Smart Learning Environments, 3, 16, 2016
4 Bulger M., Personalised Learning: The Conversations We’re Not Having, Data & Society Working Paper, 2016. 
5 Chrysafiadi, K., Virvou, M., Student modeling approaches: A literature review for the last decade, Expert Systems with Applications, Elseiver, 2013
6 Groff, J., Personalized Learning : The state of the field and future directions, Center for curriculum redesign, 2017.
7 du Boulay, B., Poulovasillis, A., Holmes, W., Mavrikis, M., Artificial Intelligence And Big Data Technologies To Close The Achievement Gap, In: Luckin, Rose ed. Enhancing Learning and Teaching with Technology. London: UCL Institute of Education Press, pp. 256–28, 2018

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