Which logical fallacy pertains to the assumption that the chemist's bad review applies to the whole product line?

The logical fallacy that pertains to the assumption that a chemist's bad review applies to the entire product line is known as composition. This fallacy occurs when one erroneously assumes that what is true for an individual part or example is also true for the whole group or product line. In this case, if a chemist has a negative opinion of one specific product, it does not logically follow that all products made by that company or within that product line share the same quality or issues.

This fallacy reflects a critical misunderstanding of how generalizations should be drawn; just because a single instance may be negative doesn’t mean every instance in that category will share the same negative quality. Therefore, when one mistakenly attributes the properties of one part to the entire set, it highlights an error in reasoning that can lead to inaccurate conclusions.