Writing is about more than slapping words onto a page or screen. It’s about creating logically connected content that’s not victimized by logic errors.
One logic error that can befall text is overgeneralization, the expansion of too few instances to many in a manner difficult to justify. For example: If, after eating a Red Delicious apple for the first time, someone said, “All apples are red,” he would be making an overgeneralization. The statement was made based on insufficient evidence to support it. In contrast, if a high school baseball player who hit below .200 for three straight years says that “I’m not a very good hitter,” he is not making an overgeneralization. He’s reached a conclusion based on sufficient, factual evidence. He’s made a generalization.
Here’s another example of an overgeneralization. This season, the Mets have won only four of their first eleven games. If, based on that, someone states that in 2011 the Mets will lose more games than they’ll win, he’s making an generalization. The evidence is insufficient to support that claim.
A key factor in determining whether a statement is a generalization or an overgeneralization is the validity and sufficiency of the supporting evidence.