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Weighing A Pig Doesn’t Make It Any Heavier

Testing is something that teachers think a lot about. What is the purpose of testing? How often should we test students? What is the best way to do it? How much lesson time should be given over to testing when it could be used for teaching? Are UK children over-tested compared to pupils elsewhere in the world?

At SGS we test all of the pupils in every subject at the end of each academic year with many subjects offering more frequent testing. Whilst this is partly to accustom students to the business of revising and ‘doing exams’ – sitting in a large room, pens clutched in a clear plastic bag and remaining calm, controversially, I think that it also helps the students to learn.

For newcomers to the testing debate, let me sketch the arguments for you. As with many aspects of life, this debate has become ritualised to the point of absurdity with both sides entirely convinced of the rightness of their cause and simply unable to comprehend another view. Many educationalists question the validity and indeed the point of testing noting the following:

  • Tests give a snapshot of performance which may not be representative; many students perform badly in tests. Tests may not give any information about the quality of the students’ learning. (The now largely abandoned alternative of coursework appears little better and is more open to outright cheating).
  • Tests inevitably mean that teachers ‘teach to the test’ and students learn how to pass a test in Biology rather than learning Biology.
  • Being good at tests may not help you in your career or in life or even in the next step of your education. How often will you need to complete an exercise under timed conditions, on your own and without reference to the internet, in a job?
  • Tests are only useful if they identify weaknesses in understanding which can then be remedied through future teaching and learning; many tests such as GCSE are terminal tests so that students give up the subject after the test and cannot address their weaknesses – a task that they probably weren’t minded to take on anyway.
  • Tests, particularly high-stakes tests, are stressful for students.
  • The old adage ‘weighing a pig doesn’t make it any heavier’ is trotted out to try to argue that testing a student doesn’t increase what they know or can do.
  • The marking of public examinations is not very reliable (sadly a good point given the relatively large number of exam grades that are changed on appeal).

Other ‘experts’, usually including government education ministers, offer the following views:

  • Tests allow students (and schools, universities, parents, employers and the government) to know how well they are doing; there must be some correlation between being good at Physics and getting a good test result in Physics.
  • Tests allow students (and everyone else) to monitor progress from one test to the next and allow teachers to intervene if progress is not being sustained.
  • Testing encourages students to work hard and study.

Let me develop the last point by suggesting that tests actually help people learn things.

Think about the last book you read or film you watched. After a few days all you will be left with is a memory of the main themes, a few detailed impressions of particular scenes and a sense of whether you liked it. We have an illusion of knowledge but we fail to notice that the substance has faded away; a test punctures our illusions and brings the reality of our lack of knowledge uncomfortably into the light. Firstly then, testing provides excellent feedback on what we have forgotten as well as what we have failed to understand. If we know that we don’t know something we are more likely to work to consolidate our knowledge and improve; if we believe that we know something then complacency will result.

Secondly, testing provides ‘retrieval practice’ (in the jargon) which means that we get better at bringing information to mind when we need it. If a student is asked the question ‘Which leaders fought at the battle of Hastings?’ and answers correctly then he or she will be able to retrieve this information more easily in the future than if the student had not been asked the question or (crucially) if he or she had simply studied the information. Essentially the more often that we try to remember something and the greater the range of contexts in which we do so the better the information is stored in our memories. When you are learning a poem off by heart and you can’t quite recall one particular line it is better to strive to think of it than to look again at the book.

Of course the test does not need to be high-stakes or even in written form: being asked a question will have the desired effect. I often ask my Physics class what they know (collectively or individually) about a topic at the start of most lessons. A few minutes of thought and discussion dispels any illusions that all of the pupils have a good knowledge of the topic as well as enabling me to repeat the key points. I hope too that it motivates them to consolidate their learning between the lessons.

Viewed in this way the point of a test is not so much to assess the effectiveness of the teaching or the effectiveness of the students’ learning but rather to help the students learn in the first place. Revision for a test and taking the test consolidates learning.