Tag Archives: modelling

Three cheers for Open Government

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Yesterday the DfE published the most detailed explanation of the Teacher Supply Model (TSM) that underpins decisions about how many new entrants to the teaching profession are needed each year. The new document is the most detailed any government has released to the general public in almost a quarter of a century. Unlike previous publications, this new one is interactive and allows interested parties to interrogate the assumptions used within the Model. It also provides forward assumptions into the 2020s for teacher supply needs. Anyone interested can find the manual and accompanying spreadsheets at https://www.gov.uk/government/publications/teacher-supply-model

The publication came about as a result of an exchange between David Laws, the Minister of State, and the Education Select Committee during one of their hearings into the issue of teacher supply and training. The Minister agreed to make the Model public and has now made good on his promise. The document is not an easy read, but the general principles are relatively easy to grasp for anyone interested in how the DfE works out the number of teachers required to enter teacher preparation programmes each year. I am sure that there will now be an informed debate on the subject

I am delighted that the current version of the TSM has reverted to calculating separate numbers for all the main curriculum subjects in secondary schools rather than just the EBacc curriculum areas with other lumped together in a composite pool.

The new Model has been used to calculate the ITT allocations for 2015 that were also announced yesterday. (More about them in another post) The good news is that the allocation for English has increased substantially. I had been puzzled, as I think had been others, about why the previous allocation figure was so far adrift of that for mathematics when both took up approximately the same amount of curriculum time in schools. That issue has been rectified for 2015 and will no doubt be welcomed by head teachers that have struggled to recruit teachers of English.

Although the data are somewhat daunting at first glance they do help those that take the time to work through them understand the potential implications of the growth in the school population over the next decade. Teaching is probably going to be a recession-proof occupation for at least the next 20 years in most parts of the country. However, that does mean that the Model shows the continuing need to recruit large numbers of new entrants to the profession. What the Model doesn’t do is identify what happens if recruitment to training falls short of target for a number of years. One solution would be to add in the shortfall to future targets, but that can inflate targets to unsustainable numbers. Such a process also doesn’t take into account of the fact that schools must cover lessons and do so be using various recruitment methods, including in the past hiring teachers from overseas.

In previous versions of the Model changes from year to year were subject to a smoothing process. That prevented too large a change from one year to the next for the benefit of providers of teacher training. That seems to have been removed. The solution still seems to be to over-allocate numbers, so that the risk at the end of the course still lies completely with the trainee that has to find a teaching post. Solving that concern is not something the TSM can do.

Minister hides his light under a Select Committee

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I needs must start this post with an apology, and a confession. Despite my interest in teacher supply and training, I missed the Minister for Schools announcement about the changes to the Teacher Supply Model. By way of mitigation, I would point out that the announcement appeared in a reply to the Education Select Committee following his appearance in front of the Committee in February to talk about underachievement by white working class children, and has seemingly been documented as DfE supplementary evidence to that inquiry. For those of you having difficulty finding what he said, the link is http://data.parliament.uk/writtenevidence/committeeevidence.svc/evidencedocument/education-committee/underachievement-in-education-of-white-working-class-children/written/7989.html

What is of interest is David Laws updating of the Committee about the Teacher Supply Model. After all the usual platitudes about how well the Department and NCTL are doing on teacher recruitment and retention, and that School Direct is proving popular on the basis that schools have been signing up for places, David Laws confirmed to the Committee that the Teacher Supply Model was being redeveloped, and that the replacement is expected to be ready by autumn 2014; presumably in time to run the numbers for teacher preparation courses starting in 2016. The Minister didn’t say whether the work on the Model was being done entirely in-house or whether the DfE had convened a group of experts to help with the necessary changes.

However, that may not matter because the Minster also told the Committee that the new Model would be available online, as previously recommended by the Committee, and advocated by myself since I first appeared in front of a Select Committee to discuss the modelling of teacher supply in 1996.

David Laws went further by stating that publication of the Model will enable public examination of the assumptions and working of the Model to help estimations of future teacher demand and projected ITT recruitment. Furthermore, he told the Committee, worked up examples will be included in the online model. This is good news, as it will help the current debate about why so few teachers of English are needed when fewer pupils are being taught by teachers qualified in the subject.

However, the fact that David Laws then went on to offer the Committee data from as far back as 2009-10 about teacher stocks and flows as if this is the latest available to the DfE raises considerable concern in my mind about his understanding of the function of planning. And there may be revealed one of the serious issues in the debate about whether we should be planning teacher training or leaving it to the market as Mr Taylor of the NCTL would seem to prefer. As I have pointed out in the past, information gleaned at one stage of an economic cycle may not be helpful in planning for another stage, so using information about teacher flows during a recession, and the deepest post-war recession there has been, may not be helpful in projecting training numbers needed in 2016, when the economy is still hopefully motoring forward, unless that is teacher supply is entirely disconnected from the wider economy.

Finally, it will be interesting to see how the teacher supply model copes with shortfalls in recruitment to training. Exposing this issue, and making sure it is debated, is a key feature that will make the current discussion about creating sufficient teacher numbers different from past periods of teacher shortage. This letter to the Select Committee has placed one more brick in the wall.

 

Teacher Supply Model: a technical description

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This week the DfE issued its response to the Select Committee request for an explanation of how the Teacher Supply Modelling (TSM) process works. It took the DfE just 20 pages of lightly argued text to explain the principles to those unfamiliar with the process. This is the third such Report in response to Select Committee inquiries into teacher supply over the past 25 years. The first, issued in 1990, and entitled Projecting the Supply and Demand of Teacher – A Technical description, ran to some 78 pages in length. The second, issued in 1998, and entitled Teacher Supply and Demand Modelling – A technical description – was even longer, at 85 pages. Both received Ministerial endorsements. The first was endorsed by The Secretary of State at the time, Kenneth Clarke, and the second by Estelle Morris, the PUS of the day. The new document is seemingly devoid of any ministerial endorsement or support.

What is clear after looking at the three documents is they manner in which the TSM process has been pared down and simplified over the years. The fact that the TSM is now only run for five secondary subjects and primary (page 23) plus a catch-all is used for other secondary subjects where the numbers are then ‘divided between other subjects proportionally according to data from recent years’ must be worthy of debate by the Select Committee. What data sources are used to establish the distribution? Is it the number of teachers in the subjects as measured by the School Workforce Survey or the amount of curriculum time allotted to each subject? The absence any overall modelling for the sciences, and a concentration on just Physics and Chemistry, is also worrying.

However, the most concerning part of the document is the single paragraph on page 20 entitled Ensuring the robustness of the TSM. The paragraph is worth quoting in full.

‘The estimates in the TSM are based closely on data trends from recent years with adjustments made from known policy changes. The robustness of the TSM is assured by sensitivity testing the model against variations in all the assumptions.’

Now the earlier documents did at least identify what some of the assumptions might be. In the new document we are told of completion rates for ITT routes in the past, but not the assumption used for School Direct that has replaced the former employment based routes into teaching. We are also told of pupil growth, and of retirements, and the outcome assumption for wastage rates of teachers leaving the profession, and for those joining both from ITT and from outside the state-funded sector. However, the comments about the success of these teachers in returning as contained in section 2.3 are somewhat opaque to say the least. Here, as elsewhere, worked examples might have added to the understanding of the process.

The modelling of wastage really identifies the whole issue with the methodology: it is essentially backward looking for its inputs. This may not matter when economic and other societal trends are relatively unchanged from year to year but it risks failing to capture major shifts in the labour market until well after they have occurred. This is why the failure to discuss the outcomes of the TSM and a range of options with the wider education community always puts the government at risk of catastrophic failure in teacher supply. The situation hasn’t been helped by the lack of a desire on the part of the wider community to systematically try to replicate the TSM for its own benefits.

The section on page 19 of the new paper dealing with stability in the ITT market and the calculation of the optimum number of ITT places seems at odds with the reality of the 2014 allocation where if Table 5 is correct the estimate of places required was 34,890, but the number allocated was  some 41,000. Now either this means that the government believed that only allocating the estimated number wouldn’t produce enough trainees or it was prepared to put the Treasury in hoc for extra fee for some 6,000 students at £9,000 a throw. What happens between now and August will be of great interest, not least to the 130 history graduates likely to be recruited above estimated need.

Missing from the document are a number of areas of importance: the policy assumptions about school budgets and the effects of the minimum funding guarantee, the  consequences of the Pupil Premium; and the possible new funding formula; the presence of Teach First, and any likely increase in the use of teachers not put through the training process informed by the TSM; the effects of shortfall in recruitment into training from year to year .This last point is covered on page 1, where it is stated, ‘undersupply is double-weighted to reflect that a future shortage of state-funded teachers would be less desirable than a future surplus’: a sensible policy option. However, it is not clear how this works in practice.

Novices to the TSM process may find the document helpful at a basic level, but, by ignoring any debate about how effective the past is as a guide to the future, and also avoiding discussions about whether the TSM is part of the process in defining ITT numbers that Ministers can then change on the advice of others, the document provides little insight to the decisions taken during the past two years about how many teachers to train. Possibly, we will learn more when Mr Taylor speaks at the North of England Education Conference next week, but a lingering doubt must remain that as he said at the same conference last year:

“In the future I would like to see local areas deciding on the numbers of teachers they will need each year rather than a fairly arbitrary figure passed down from the Department for Education. … I don’t think Whitehall should be deciding that nationally we need 843 geography teachers, when a more accurate figure can be worked out locally.