According to the Gestaltists, the whole stimulus pattern determines the organization of its own parts. The Gestalt psychologists believed that all the grouping laws are particular examples of one general principle- the law of pragnanz. The law of pragnanz is a term to refer to the tendency to perceive figures as good, regular, and simple with minimum cognitive effort. Therefore, this law is also known as the law of good figure.
The laws of grouping and figure ground relationship operate to make us see good simple figures. On the other hand, the law of pragnanz operates on the fact that we like to see regular and simple forms, rather than irregular forms. According to the Gestalt psychologists, if there are irregularities in a figure, those are overlooked and the figure is perceived as a symmetrical, complete, simple, and good figure.
In the laws of perceptual organization discussed above, the Gestalt psychologists emphasized the role of form qualities of objects in our perception. All these factors are called the structural factors in perception. Besides the above organizing factors, they have also recognized the importance of familiarity and set or attitude in influencing our perception.
For example, if some of the dots in a collection makeup the outline of a face or of any familiar object, we can easily perceive it out of the background. Similarly, if the observer is actively looking for a certain figure in an ambiguous presentation, he is more likely to see that particular figure.
However, the Gestalt psychologists have warned not to overemphasize the roles of such factors like familiarity and set. According to them, the laws of organization based on the form qualities of objects are more primitive factors influencing perception.