This section explores the ways that psychologists use standardised tests
The development of standardised tests
Much of developmental research is looking for differences between children in order to explore the factors that influence such variations. A task on which all children perform in exactly the same way, no matter what age they are or whatever their background, is unlikely to be of much interest to any researchers.
So one of the things that people designing tasks are concerned with is to make sure that children’s performance shows sufficient variation from one individual to another and sufficient variation between children of different ages.
An aspect that researchers have to bear in mind is to avoid what are called floor and ceiling effects. These effects arise when the developmental tasks do not allow sufficient range in children’s responses to differentiate between some of the children at the upper or lower extremes of performance.
Thus, if one in three children always scores 100% on a particular task, and another one in three scores 0%, then the task is only discriminating among the group getting scores between 1 and 99%, only one-third of the population. The ceiling effect is where a substantial number of children score at a maximum level, and hence it is not possible to distinguish between them in terms of their performance on the task. The floor effect refers to the group at the other end of the distribution, those children who all score 0% and hence cannot be distinguished between either.
An example of why this may be important is given by a case in which an intervention to improve the reading ability of poor readers might fail to show effects because the test used to assess reading ability has a marked floor effect. Thus, children whose reading ability genuinely improved as a result of the intervention might still score at or around zero because the test does not discriminate well between poor readers, although it may discriminate well between average and better than average readers.
Testing, Context and Language
Writing in Children's Minds, Margaret Donaldson suggested that when children are faced with tasks set them by researchers, they find such tasks much easier if they make some sort of human sense. In the ‘Three Mountains’ task, it can be seen that a child’s performance on a task cannot be easily separated from the context in which the task is located. Modern ideas of situated cognition (such as those put forward by WJ Clancey in the article Situated cognition: how representations are created and given meaning) stress this point.
In addition, it is easy to assume that children understand language in the same way as adults and thus they will find it as easy to follow instructions or to respond to questions as adults do. However, it often seems that children will place more reliance on non-verbal cues or the context of the question than would adults. In the assessment of conservation the context of the question can have a powerful effect
These factors can affect the validity of the assessment, and affect the relation between competence and performance. Good standardised tests attempt to avoid these problems.
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Content last updated: 19/02/2007
