Haber and Levin

Haber and Levin’s work was based around an ongoing argument regarding whether or not perception should be classed as ‘top-down’ or ‘bottom-up’.

Aim

The aim of this study was to see if participants could estimate the distance of objects, based on their apparent size. Haber and Levin were also interested in identifying if perception was a ‘top-down’ process.

Method

Nine male college students, all who had previously been tested for good eyesight, were taken to a large grassy field which was surrounded on three sides by trees. By the time the participants arrived, the field had already been divided and prepared into four separate sections, which were as follows:

• Section one acted as the arrival area and was therefore empty
• In section two, the experimenters had placed, at random distances, 15 objects which have a clear, well-known size, such as a standard door
• In section three, the experimenters had put 15 objects whose sizes could be different
• In section four, the experimenters had put 15 cardboard cut-outs of three geometric figures, i.e. circles, rectangles and triangles.

A repeated measures design was used for this experiment. Participants were taken in a line to the centre of the field through the first empty section and were then asked to face a different section of the field in groups of three.

Each participant was given a clipboard and they were asked to write down their estimates about how far away they thought the objects were. When all participants had made all of their estimates the groups turned in a new direction and repeated the task until they had looked at all 45 objects in all of the three different directions.

Results

• Participants were able to most accurately estimate distance for the objects which were of a standard size. Estimates were good for standard size objects for both those that were close and those that were further away
• Estimates for the other objects and for the cut-outs of shapes were not as accurate.

Conclusion

Haber and Levin concluded that participants found it easier to estimate the distance of standard size objects because they were relying on previous experiences of those objects. Participants expected objects such as a door or a milk bottle to be a certain size, and therefore they could use this previous knowledge to work out how far they were away based on their relative size.

Because the other objects will not have a standard size, participants found the task to be more difficult and were therefore less accurate in recalling the distance.

The results give credibility to the constructivist theory of perception, because participants were able to judge distance related to previous experience of the objects that they were seeing. If the direct theory were right, the participants would have been able to judge instinctively the distance of the non-standard sized objects and this was not the case.

Strengths of the study

• Some evidence was given for the constructivist theory of perception, which has been used to conduct more research in this area.

Weaknesses of the study

• It is very difficult to draw any solid conclusions from an experiment with just nine participants, as the sample is not representative
• The sample was also gender biased as they were all male; women may have been able to estimate the distances differently
• The task and the setting were artificial and this means that the results are not easily relatable to real life.