4.2 Experiments

The experiment is a method which builds further on the systematic, controlled approach just described. Experiments are typically used to gain insights into how people deal with the world around them – for instance, how they remember information, attend to things, or recognise people’s faces. Experiments put claims such as ‘individuals with autism have very good memories’ to a critical test, so countering false or misguided opinions.

Say that a researcher sets out to explore memory ability in autistic people. Firstly a hypothesis is formulated. This might state, for instance, that memory for words or faces will differ between autistic and neurotypical people. An experimental group of autistic people and a matched neurotypical control group will take part in a memory test: for instance, seeing or hearing a list of words and recalling them after an interval. The number of words recalled by each participant would be one simple measure of their memory in this task. From this the researcher calculates the average score for each group and compares them. Statistical tests are used to evaluate the probability that any apparent difference between the groups has occurred by chance. A result that is highly unlikely to have occurred by chance is said to be statistically significant, enabling a reasonably confident conclusion that the hypothesis has been confirmed.

The same basic framework can also help determine whether or not an intervention (treatment) is useful, by comparing changes in a group of autistic children receiving the intervention with an age- and intellectually-matched group of children also with autism, but not receiving the intervention.