Strengths:The main strength of this experiment is the control of variables. Variables were controlled such as intelligence, gender and developmental disorders. The researchers were able to ensure that the differences between the scores of the three groups of participants were something to do with being autistic, and not due to other extraneous variables such as intelligence levels.Furthermore the experiment was further standardised in that every participant was tested in the same way. The photographs were presented in the same way to each participant, which ensured that the researchers could claim with some certainty that the IV (being autistic) was causing the poor performance on the Eyes Task. The experiment also collected quantitative data in the form of scores on the Eye Tasks enabling the researchers to carry out detailed statistical analysis of the results.Weaknesses: It is possible to question the ecological validity of the experiment. Some of the participants were tested at a lab in a University and this strange situation may have had an effect on performance. Probably more importantly the Eye Task test can be questioned as it is an unusual task which is much simpler than the demands of real live social situations. For example, in the real world people and their emotions are not static. The Eyes Task may lack validity, because it may not be actually measuring theory of mind. However, the researchers defend the validity in a number of ways. First, the target words are actual mental state terms. Secondly, these are not just emotion terms, but include terms describing cognitive mental states. This is therefore more than just an emotion perception test. Thirdly, the pattern of results from the Eyes Task mirrored the pattern of performance on the Happe Strange Stories task - an existing advanced theory of mind task. Therefore, the Eyes Task has concurrent validity.