In this series of posts I record my notes from Daisy Christodolou’s book “Making good progress? The future of Assessment for Learning” It is quite excellent. You can buy a copy here.

Making valid inferences

If the best way to develop a skill is to practice the components that make it then it is hard to use the same type of task to assess formatively and summatively.

Summative assessment tasks aim to generalise and create shared meaning beyond the context in which they are made. Pupils given one summative judgement in one school should be getting a similar judgement in another school.

Formative assessment aims to give teachers and students information to form the basis for successful action in improving performance.

Although, at times, a summative task may be able to repurposed as a formative task, generally different purposes pull assessments in different directions. The purpose of an assessment does impact on its design which makes it harder to simplistically re-purpose it.

Assessments need to be thought of in terms of there reliability and their validity. The validity of an assessment refers to the inferences that we can draw from its results. The reliability is a measure of how often the assessment would produce the same results with all other factors controlled.

The example of timing of mocks comes to mind. Whether you want these to be a summative or a formative assessment will affect when you favour setting them.

Sampling (the amount of knowledge from a particular domain assessed by an assessment) affects the validity of an assessment. Normally in summative assessments questions sample the domain, they do not cover it in its entirety.

Some assessment do not have to sample. If the domain they are measuring (letters of the alphabet) is small this isn’t a problem. Further along the educational pathway this becomes harder.

Assessments also need to be reliable. Unreliability is introduced into assessments through sampling, the marker (different markers may disagree) and the student (student performance can vary day to day).

Models of assessment include the quality model and the difficulty model. Sources of unreliability affect each of them in different ways. Quality model requires markers to judge how well a student has performed (think figure skating), difficulty model requires pupils to answer questions of increasing difficulty (think pole-vault).

There is a trade-off between reliability and validity. A highly reliable MCQ assessment (reduction in sampling and marker error) may limit how many inferences you can make from the assessment, you may be unable to use this as a summative assessment as it doesn’t properly match up with the final assessment.

However reliablity is a prerequisite for validity. If an assessment is not reliable then the inferences drawn from it, its validity, is also not reliable. We can’t support valid inferences.

You may well be able to create an exciting and open assessment task which corresponds to real-world tasks; however, if a pupil can end up with a wildly different mark depending on what task they are allocated, and who marks it, the mark cannot be used to support any valid inferences.

Summative assessments are required to support large and broad inferences about how pupils will perform beyond the school and in comparison to other peers. In order for such inferences to be valid they must be consistent.

Shared meanings impose restrictions on the design and administration of assessments. There are specific criteria needed for this. To distinguish between test takers, assessments need items of moderate difficulty and assessments must sample. Samples need to be carefully considered and representative.

The main inference needed for formative assessments is how to proceed next. Assessment still needs to be reliable but the inferences do not need to be shared even with kids in the same room. I can therefore help some kids more than others. It is about methods. It needs to flexible and responsive.

The nature of inference posses a restriction on assessment. Trying to make summative inferences from tasks that have been designed for formative assessment use is hard to do reliably without sacrificing flexibility and responsiveness.

Assessment theory triangulates with cognitive psychology. The process of aquiring skills is different from the product, the methods of assessing the process and the product are different too.

Formative assessments need to be developed by breaking down the skills and tasks that feature in summative assessments into tasks that will give valid feedback about how pupils are progressing towards that goal.

They can be integrated into one system, to be discussed in a later chapter.

Most schools make the mistake of summatively assessing all too frequently.

 

In this series of posts I record my notes from Daisy Christodolou’s book “Making good progress? The future of Assessment for Learning” It is quite excellent. You can buy a copy here.

Aims and methods

The generic skills approach implies that skills are transferable and that the best way to develop a skill is to practice that skill. It is based on the analogy of the mind acting as a muscle.

There are examples of curriculums that follow this model like the RSA opening minds curriculum; it is interesting to contrast this to the core knowledge curriculum mentioned by Hirsch and the DI models.

Instruction based on this model is organised around developing transferable skills through projects where students practice authentic performances.

However research from 50 years of cognitive science shows us that skill is domain specific and dependent on knowledge. The examples of studies into Chess grand masters is given. These were the earliest experiments but have been reliably repeated in other knowledge domains. There are multiple lines of evidence that suggest the same thing (A bit like evolutionary theory).

Complex skills depend on mental models which are specific to a particular domain. These models are built in long term memory. They can be drawn on to solve problems and prevent working memory from being overloaded.

Working memory is highly limited and relying on it to solve problems is highly ineffective. Learning is the process of aquiring these mental models. Performance is the process of using them.

Formative assessment should aim to assess how these mental models are being developed. Summative assessment measures the performance or act of using those mental models.

Even scientific thinking is domain specific. One cannot evaluate anomalies or the plausibility of a hypothesis without domain specific knowledge.

The adoption of generic skills theory leads to a practical flaw: lessons are too careless about the exact content knowledge that is included in them (this also ties in with Hirsch’s ideas that individualisation leads to a reduction in knowledge). If skills are not transferable we need to be very careful about what the content of a lesson is. Specifics matter.

The educational aim of developing generic skills is sound but we need to think about the method. We can develop critical thinking only by equipping learners with knowledge. Good generic readers or problem solvers have a wide background knowledge.

Aquiring mental models is an active process. project based lessons can work as they help students to make the knowledge their own, its just that sufficient care and attention to the content that is to be learned is applied.

Specific and focussed practice is what is needed to develop skill. As shown by the work of K. Anders Ericsson, there is a difference between deliberate practice and performance. Deliberate practice builds mental models, while performance uses them.

What is learning and how is it different from performance? Learning is the creation of mental models of reality in long term memory. Copying what experts do (performing) is not a useful way of developing the skill of the expert because they do not build the mental models. Instead these lessons will overwhelm working memory and will be counter-productive.

Generic skill models only allow feedback that is generic, it does not allow are feedback to tell students exactly how to improve. “think from multiple perspectives more” is not useful advice if kids don’t know how to do it.

Models of progression are needed to show the progress that students are making.

Peer and self assessment can be useful so long as they are used appropriately. The Dunning Kruger effect shows us that novices cannot judge their performance accurately (does this contradict Hattie’s claim about self reported grades that kids know where they are at?). Developing pupils ability involves developing their ability to pervcieve quality. We cannot expect them to self assess complex tasks and showing them excellent work is not enough to develop excellence. Particular aspects of work need to be highlighted by the teacher.

To develop skill we need lots of specific knowledge and practice at using that knowledge. This helps to close the knowing-doing gap.