Archive for May, 2015

Adaptive learning providers make much of their ability to provide learners with personalised feedback and to provide teachers with dashboard feedback on the performance of both individuals and groups. All well and good, but my interest here is in the automated feedback that software could provide on very specific learning tasks. Scott Thornbury, in a recent talk, ‘Ed Tech: The Mouse that Roared?’, listed six ‘problems’ of language acquisition that educational technology for language learning needs to address. One of these he framed as follows: ‘The feedback problem, i.e. how does the learner get optimal feedback at the point of need?’, and suggested that technological applications ‘have some way to go.’ He was referring, not to the kind of feedback that dashboards can provide, but to the kind of feedback that characterises a good language teacher: corrective feedback (CF) – the way that teachers respond to learner utterances (typically those containing errors, but not necessarily restricted to these) in what Ellis and Shintani call ‘form-focused episodes’[1]. These responses may include a direct indication that there is an error, a reformulation, a request for repetition, a request for clarification, an echo with questioning intonation, etc. Basically, they are correction techniques.

These days, there isn’t really any debate about the value of CF. There is a clear research consensus that it can aid language acquisition. Discussing learning in more general terms, Hattie[2] claims that ‘the most powerful single influence enhancing achievement is feedback’. The debate now centres around the kind of feedback, and when it is given. Interestingly, evidence[3] has been found that CF is more effective in the learning of discrete items (e.g. some grammatical structures) than in communicative activities. Since it is precisely this kind of approach to language learning that we are more likely to find in adaptive learning programs, it is worth exploring further.

What do we know about CF in the learning of discrete items? First of all, it works better when it is explicit than when it is implicit (Li, 2010), although this needs to be nuanced. In immediate post-tests, explicit CF is better than implicit variations. But over a longer period of time, implicit CF provides better results. Secondly, formative feedback (as opposed to right / wrong testing-style feedback) strengthens retention of the learning items: this typically involves the learner repairing their error, rather than simply noticing that an error has been made. This is part of what cognitive scientists[4] sometimes describe as the ‘generation effect’. Whilst learners may benefit from formative feedback without repairing their errors, Ellis and Shintani (2014: 273) argue that the repair may result in ‘deeper processing’ and, therefore, assist learning. Thirdly, there is evidence that some delay in receiving feedback aids subsequent recall, especially over the longer term. Ellis and Shintani (2014: 276) suggest that immediate CF may ‘benefit the development of learners’ procedural knowledge’, while delayed CF is ‘perhaps more likely to foster metalinguistic understanding’. You can read a useful summary of a meta-analysis of feedback effects in online learning here, or you can buy the whole article here.

I have yet to see an online language learning program which can do CF well, but I think it’s a matter of time before things improve significantly. First of all, at the moment, feedback is usually immediate, or almost immediate. This is unlikely to change, for a number of reasons – foremost among them being the pride that ed tech takes in providing immediate feedback, and the fact that online learning is increasingly being conceptualised and consumed in bite-sized chunks, something you do on your phone between doing other things. What will change in better programs, however, is that feedback will become more formative. As things stand, tasks are usually of a very closed variety, with drag-and-drop being one of the most popular. Only one answer is possible and feedback is usually of the right / wrong-and-here’s-the-correct-answer kind. But tasks of this kind are limited in their value, and, at some point, tasks are needed where more than one answer is possible.

Here’s an example of a translation task from Duolingo, where a simple sentence could be translated into English in quite a large number of ways.

i_am_doing_a_basketDecontextualised as it is, the sentence could be translated in the way that I have done it, although it’s unlikely. The feedback, however, is of relatively little help to the learner, who would benefit from guidance of some sort. The simple reason that Duolingo doesn’t offer useful feedback is that the programme is static. It has been programmed to accept certain answers (e.g. in this case both the present simple and the present continuous are acceptable), but everything else will be rejected. Why? Because it would take too long and cost too much to anticipate and enter in all the possible answers. Why doesn’t it offer formative feedback? Because in order to do so, it would need to identify the kind of error that has been made. If we can identify the kind of error, we can make a reasonable guess about the cause of the error, and select appropriate CF … this is what good teachers do all the time.

Analysing the kind of error that has been made is the first step in providing appropriate CF, and it can be done, with increasing accuracy, by current technology, but it requires a lot of computing. Let’s take spelling as a simple place to start. If you enter ‘I am makeing a basket for my mother’ in the Duolingo translation above, the program tells you ‘Nice try … there’s a typo in your answer’. Given the configuration of keyboards, it is highly unlikely that this is a typo. It’s a simple spelling mistake and teachers recognise it as such because they see it so often. For software to achieve the same insight, it would need, as a start, to trawl a large English dictionary database and a large tagged database of learner English. The process is quite complicated, but it’s perfectably do-able, and learners could be provided with CF in the form of a ‘spelling hint’.i_am_makeing_a_basket

Rather more difficult is the error illustrated in my first screen shot. What’s the cause of this ‘error’? Teachers know immediately that this is probably a classic confusion of ‘do’ and ‘make’. They know that the French verb ‘faire’ can be translated into English as ‘make’ or ‘do’ (among other possibilities), and the error is a common language transfer problem. Software could do the same thing. It would need a large corpus (to establish that ‘make’ collocates with ‘a basket’ more often than ‘do’), a good bilingualised dictionary (plenty of these now exist), and a tagged database of learner English. Again, appropriate automated feedback could be provided in the form of some sort of indication that ‘faire’ is only sometimes translated as ‘make’.

These are both relatively simple examples, but it’s easy to think of others that are much more difficult to analyse automatically. Duolingo rejects ‘I am making one basket for my mother’: it’s not very plausible, but it’s not wrong. Teachers know why learners do this (again, it’s probably a transfer problem) and know how to respond (perhaps by saying something like ‘Only one?’). Duolingo also rejects ‘I making a basket for my mother’ (a common enough error), but is unable to provide any help beyond the correct answer. Automated CF could, however, be provided in both cases if more tools are brought into play. Multiple parsing machines (one is rarely accurate enough on its own) and semantic analysis will be needed. Both the range and the complexity of the available tools are increasing so rapidly (see here for the sort of research that Google is doing and here for an insight into current applications of this research in language learning) that Duolingo-style right / wrong feedback will very soon seem positively antediluvian.

One further development is worth mentioning here, and it concerns feedback and gamification. Teachers know from the way that most learners respond to written CF that they are usually much more interested in knowing what they got right or wrong, rather than the reasons for this. Most students are more likely to spend more time looking at the score at the bottom of a corrected piece of written work than at the laborious annotations of the teacher throughout the text. Getting students to pay close attention to the feedback we provide is not easy. Online language learning systems with gamification elements, like Duolingo, typically reward learners for getting things right, and getting things right in the fewest attempts possible. They encourage learners to look for the shortest or cheapest route to finding the correct answers: learning becomes a sexed-up form of test. If, however, the automated feedback is good, this sort of gamification encourages the wrong sort of learning behaviour. Gamification designers will need to shift their attention away from the current concern with right / wrong, and towards ways of motivating learners to look at and respond to feedback. It’s tricky, because you want to encourage learners to take more risks (and reward them for doing so), but it makes no sense to penalise them for getting things right. The probable solution is to have a dual points system: one set of points for getting things right, another for employing positive learning strategies.

The provision of automated ‘optimal feedback at the point of need’ may not be quite there yet, but it seems we’re on the way for some tasks in discrete-item learning. There will probably always be some teachers who can outperform computers in providing appropriate feedback, in the same way that a few top chess players can beat ‘Deep Blue’ and its scions. But the rest of us had better watch our backs: in the provision of some kinds of feedback, computers are catching up with us fast.

[1] Ellis, R. & N. Shintani (2014) Exploring Language Pedagogy through Second Language Acquisition Research. Abingdon: Routledge p. 249

[2] Hattie, K. (2009) Visible Learning. Abingdon: Routledge p.12

[3] Li, S. (2010) ‘The effectiveness of corrective feedback in SLA: a meta-analysis’ Language Learning 60 / 2: 309 -365

[4] Brown, P.C., Roediger, H.L. & McDaniel, M. A. Make It Stick (Cambridge, Mass.: Belknap Press, 2014)

Advertisements

Back in December 2013, in an interview with eltjam , David Liu, COO of the adaptive learning company, Knewton, described how his company’s data analysis could help ELT publishers ‘create more effective learning materials’. He focused on what he calls ‘content efficacy[i]’ (he uses the word ‘efficacy’ five times in the interview), a term which he explains below:

A good example is when we look at the knowledge graph of our partners, which is a map of how concepts relate to other concepts and prerequisites within their product. There may be two or three prerequisites identified in a knowledge graph that a student needs to learn in order to understand a next concept. And when we have hundreds of thousands of students progressing through a course, we begin to understand the efficacy of those said prerequisites, which quite frankly were made by an author or set of authors. In most cases they’re quite good because these authors are actually good in what they do. But in a lot of cases we may find that one of those prerequisites actually is not necessary, and not proven to be useful in achieving true learning or understanding of the current concept that you’re trying to learn. This is interesting information that can be brought back to the publisher as they do revisions, as they actually begin to look at the content as a whole.

One commenter on the post, Tom Ewens, found the idea interesting. It could, potentially, he wrote, give us new insights into how languages are learned much in the same way as how corpora have given us new insights into how language is used. Did Knewton have any plans to disseminate the information publicly, he asked. His question remains unanswered.

At the time, Knewton had just raised $51 million (bringing their total venture capital funding to over $105 million). Now, 16 months later, Knewton have launched their new product, which they are calling Knewton Content Insights. They describe it as the world’s first and only web-based engine to automatically extract statistics comparing the relative quality of content items — enabling us to infer more information about student proficiency and content performance than ever before possible.

The software analyses particular exercises within the learning content (and particular items within them). It measures the relative difficulty of individual items by, for example, analysing how often a question is answered incorrectly and how many tries it takes each student to answer correctly. It also looks at what they call ‘exhaustion’ – how much content students are using in a particular area – and whether they run out of content. The software can correlate difficulty with exhaustion. Lastly, it analyses what they call ‘assessment quality’ – how well  individual questions assess a student’s understanding of a topic.

Knewton’s approach is premised on the idea that learning (in this case language learning) can be broken down into knowledge graphs, in which the information that needs to be learned can be arranged and presented hierarchically. The ‘granular’ concepts are then ‘delivered’ to the learner, and Knewton’s software can optimise the delivery. The first problem, as I explored in a previous post, is that language is a messy, complex system: it doesn’t lend itself terribly well to granularisation. The second problem is that language learning does not proceed in a linear, hierarchical way: it is also messy and complex. The third is that ‘language learning content’ cannot simply be delivered: a process of mediation is unavoidable. Are the people at Knewton unaware of the extensive literature devoted to the differences between synthetic and analytic syllabuses, of the differences between product-oriented and process-oriented approaches? It would seem so.

Knewton’s ‘Content Insights’ can only, at best, provide some sort of insight into the ‘language knowledge’ part of any learning content. It can say nothing about the work that learners do to practise language skills, since these are not susceptible to granularisation: you simply can’t take a piece of material that focuses on reading or listening and analyse its ‘content efficacy at the concept level’. Because of this, I predicted (in the post about Knowledge Graphs) that the likely focus of Knewton’s analytics would be discrete item, sentence-level grammar (typically tenses). It turns out that I was right.

Knewton illustrate their new product with screen shots such as those below.

Content-Insight-Assessment-1

 

 

 

 

 

Content-Insight-Exhaustion-1

 

 

 

 

 

 

 

They give a specific example of the sort of questions their software can answer. It is: do students generally find the present simple tense easier to understand than the present perfect tense? Doh!

It may be the case that Knewton Content Insights might optimise the presentation of this kind of grammar, but optimisation of this presentation and practice is highly unlikely to have any impact on the rate of language acquisition. Students are typically required to study the present perfect at every level from ‘elementary’ upwards. They have to do this, not because the presentation in, say, Headway, is not optimised. What they need is to spend a significantly greater proportion of their time on ‘language use’ and less on ‘language knowledge’. This is not just my personal view: it has been extensively researched, and I am unaware of any dissenting voices.

The number-crunching in Knewton Content Insights is unlikely, therefore, to lead to any actionable insights. It is, however, very likely to lead (as writer colleagues at Pearson and other publishers are finding out) to an obsession with measuring the ‘efficacy’ of material which, quite simply, cannot meaningfully be measured in this way. It is likely to distract from much more pressing issues, notably the question of how we can move further and faster away from peddling sentence-level, discrete-item grammar.

In the long run, it is reasonable to predict that the attempt to optimise the delivery of language knowledge will come to be seen as an attempt to tackle the wrong question. It will make no significant difference to language learners and language learning. In the short term, how much time and money will be wasted?

[i] ‘Efficacy’ is the buzzword around which Pearson has built its materials creation strategy, a strategy which was launched around the same time as this interview. Pearson is a major investor in Knewton.