Ask the expert: Diagnostic assessment

In this ‘Ask the expert’, Emily Jones, Research Director at NFER, answers some FAQs on diagnostic assessment.

What is diagnostic assessment?

In some respects diagnostic assessment is similar to formative assessment in that it examines the knowledge and skills that a pupil has already learnt. The difference between the two assessment types lies in how the gained understanding is used by the teacher. Formative assessment is usually carried out within a topic to understand current learning and address any areas in which the pupil has difficulties or gaps in knowledge and understanding. Diagnostic assessment, on the other hand, is usually carried out at the start of a new topic to identify what pupils already know and can do, enabling the teaching content of the new topic to be planned.

During the course of a school year, a number of topics will be covered in each subject. Those taught later in the school year often build on initial building blocks taught through topics earlier in the school year. For this reason, the spring term can often be a good time to carry out diagnostic assessments as the learning in the first part of the school year can be evaluated before embarking on topics which progress learning to more complex ideas.

What should I look for in diagnostic assessment outcomes?

A diagnostic assessment should enable teachers to compare pupil performance, not just within the class or school, but also to the national picture. For example, a teacher may learn from an assessment that all the pupils in the class have a similar level of knowledge and skill in a topic. However, without comparison to the national cohort the teacher would not know if this standard is appropriate, or whether pupils elsewhere generally have a greater depth of understanding, giving those pupils a more solid basis from which to move on to new elements.

Sometimes the reasons why a pupil is having difficulty are clear, but this is not always the case! It can therefore also be helpful if diagnostic assessments provide an indication of the misunderstanding or misconception that lies behind the error that the pupil is making. This makes it easier to plan material which will take into account and correct the pupil’s thinking.  

How can diagnostic assessment be used to inform ongoing teaching?

Diagnostic assessment can be carried out at a variety of levels. The whole class or cohort may have a weaker understanding than expected or desired in some aspects of a topic. In such cases, curriculum co-ordinators and subject specialists can use the information gleaned from diagnostic assessments to inform continuous professional development. In other situations, teachers may identify one stumbling block that, once corrected, allows the entire class to progress their understanding. Alternatively, diagnostic assessment can be used with smaller groups of pupils or even individuals. For example, diagnostic assessment may provide insight on how to extend the learning for a group of high achievers, or it may inform some targeted intervention for a less able pupil. The important point is that after the assessment, the teacher shares the information with the pupil so that they too understand where they lack knowledge or have a misunderstanding and can collaboratively work to correct it.

Did you know?

NFER Spring tests for years 3-6 can help you monitor progress throughout the academic year, and include diagnostic marking guidance to support analysis of common errors. Find out more here.

Written by Emily Jones, Research Director at NFER.

Emily has been with NFER since 2001 and has worked on a wide range of projects, centred on developing test materials in science and mathematics, including for the Key Stage 1 and Key Stage 2 statutory tests in England and the Australian statutory NAP test.

Emily is responsible for the development of NFER tests in mathematics, reading, grammar and punctuation and spelling. She is also a consultant member of the TIMSS 2019 Science and Maths Item Review Committee and in recent years has contributed to the development of their new practical science e-assessment tasks, as well as developing and trialling the standard science questions.

Do you have a question on assessment that you’d like to put to one of our assessment team? Send it through to us at assessmenthub@nfer.ac.uk.