What principle is Sylvia struggling to understand when she feels she is getting less hot dog than Judy?

The principle that Sylvia is struggling to understand when she feels she is getting less hot dog than Judy relates to the concept of conservation. In psychology, particularly in developmental psychology, conservation refers to the understanding that certain properties of objects, such as volume, mass, and number, remain constant even when their forms or arrangements change.

For instance, if Sylvia and Judy have hot dogs cut into different shapes or sizes, Sylvia might perceive that she has less even if the actual amount of hot dog is the same. This misunderstanding highlights a key developmental stage where children learn that the amount of substance does not change despite transformations in appearance.

On the other hand, equivalence pertains to the concept of equal amounts or values, which is relevant but not the primary principle involved in Sylvia's misunderstanding in this context. Scale relates to the proportion between sizes or dimensions, which does not directly address her perception of quantity. Comparative analysis involves evaluating differences between items, but again, it is not the core principle that Sylvia is grappling with. Therefore, conservation is the key concept that explains Sylvia's struggle with her perception of quantity.