Where is the evidence to support differentiation?Posted: May 16, 2017
Following my last post, a number of people challenged me on Twitter about differentiation. I was not surprised by this. Differentiation is an article of faith within schools of education and questioning it is seen as heresy.
Let me make clear that I am not against all forms of differentiation. Part of the problem is the elasticity of the term. I have had discussions with some who regard the practice of placing students in different classes based upon prior achievement as ‘differentiation’. The evidence for ability grouping is ambiguous but at least it has the potential to be efficient. I also employ practices that could be described as ‘differentiation’ in my own work. For instance, I often ask some students to work on problems while I reexplain a concept to a section of the class.
Yet to many teachers and teacher educators, differentiation means something quite specific. It means grouping students within a class and planning different activities for these groups as well as perhaps providing options for students. For instance, this article in The Conversation describes a process of differentiation that allows students to demonstrate what they have learned through alternative means:
“Actually, differentiation is about teachers providing choice to avoid discriminating against students who may be disadvantaged by ‘one size fits all’ approaches…
It does mean that students with expressive language difficulties or dyspraxia, for example, who experience difficulties with writing are given the opportunity to demonstrate their learning in other ways.
This was famously demonstrated in the movie The Blind Side where Michael Oher’s teachers conducted oral assessments, enabling him to successfully demonstrate his learning.”
I think this is a flawed idea. If students struggle with writing then doing less writing than their peers hardly seems like a plan to address this. Over time, if this kind of differentiation is the norm across classes then we should see a widening gap in writing ability between the child with language difficulties and his or her classmates. Perhaps we intend to just give writing away? I’m not prepared to do that.
I am also of the view that within-class differentiation is impractical to plan and inefficient to deliver. It requires a teacher to manage multiple groups engaged in different tasks. In a sixty minute lesson with a class divided into five groups, the teacher is able to spend a maximum of twelve minutes with each group. And that’s before you take out all the time spent just managing the arrangement; “The table at the back need to focus while I talk to these guys at the front. Thank you. Wait, why are you wandering around, Carl?” These factors are likely to be part of the problem with the L3 programme in New South Wales.
So I have reasoned arguments against differentiation and I think they are valid ones. However, I also have some empirical evidence. A large scale study was carried out across a number of states in the U.S. One of the authors of the study was Carol Ann Tomlinson of the University of Virginia, probably the world’s greatest proponent of differentiation. So you would imagine that they gave differentiation a pretty good go. Yet they couldn’t get it to work. This may be because it was hard to train teachers to do it correctly, it may be because differentiation is flawed in principle or it may, as I suspect, be a bit of both. It’s not promising, however you look at it.
If we accept that whole class teaching is the default and that differentiation involves teachers doing something different, then the burden of proof actually lies with differentiation’s proponents. This burden appears even greater when you consider that every school of education teaches differentiation as best practice and it is required by the Australian Professional Standards for Teachers. You would think there must be tons of evidence. So it should be straightforward – my arguments should be easily falsified by citing studies that show that differentiation leads to enhanced educational outcomes.
The most popular framework for differentiation in Australia seems to be Universal Design for Learning (UDL). I have my doubts about this model but an advocate of differentiation pointed me to a paper with the promising title of, “The effectiveness of universal design for learning: a meta-analysis of literature between 2013 and 2016.” Perhaps this would conclusively prove me wrong? Perhaps it would demonstrate clear evidence for the effectiveness of this form of differentiation? The abstract states:
“Universal Design for Learning (UDL) is often promoted as an inclusive teaching methodology for supporting all students within diverse contemporary classrooms. This is achieved by proactively planning to the edges of a classroom by thinking of all the potential needs of students. To examine its effectiveness, a meta-analysis was conducted on empirical research, containing pre- and post-testing, published in peer-reviewed journals between 2013 and 2016 (N = 18). Results from this analysis suggest that UDL is an effective teaching methodology for improving the learning process for all students. The impact on educational outcomes has not been demonstrated. The implications of this study will be discussed.” [my emphasis]
The paper lists many positive experiences of using UDL and positive effects on how teachers and students feel, but the evidence for impact on educational outcomes is indeed lacking. This is a problem because it is possible to make students and teachers feel positive about pretty much any innovation. What we really need to know is that it leads to more learning.
It was also suggested to me that lots of teachers use differentiation every day and find it effective. How can I dismiss these teachers and their experiences? Do I not value their opinions? Unfortunately, testimonials are an unreliable form of evidence. If I were able to produce a list of teachers who said differentiation does not work for them – which I reckon I probably could – then would this refute such an argument? I suspect I would be told that they must not be doing it properly.
Finally, I was linked to a piece that attempts to explain why teachers are sometimes resistant to differentiation. It’s fascinating. I was particularly taken by this claim:
“Research clearly indicates that students will typically perform better on standardized tests when they have had the opportunity to learn in preferred modes, even if the test is not in their preferred mode. “
Unfortunately, there is no link to this research or a reference to follow. Preferred modes of learning are known more commonly as ‘learning styles’ and this statement expresses the ‘meshing hypothesis’ that matching instruction to a student’s preferred learning style is more effective than not matching the instruction in this way. This hypothesis has been extensively investigated and no supporting evidence has been found.
There are plenty of educational strategies that, like differentiation, lack a solid evidence base. That’s not necessarily a problem. Teachers should be presented with these strategies and a fair appraisal of the research. They may then – individually or as part of a whole-school approach – make informed decisions about which ones to apply.
What I object to is the enforcement of differentiation through teacher standards and the misleading claims that it is best practice or that teachers who don’t apply a particular form of differentiation are discriminating against groups of students. That is coercive. It might be justified if the evidence for the effectiveness of differentiation was strong but it clearly is not.