Success in the digital age depends on comprehending complex text. Within any complex text, the majority of words come from a very small group of words in written English. On average, 90% of the words in a text are drawn from 4,000 simple word families (e.g., help, helping, helps, helped, helper but not helpless or helpful). The other 10% of the words in texts come from the remaining 300,000 (or more) words in the English language. Many words in this latter group don’t occur often (less than once per million) but, as extended vocabulary, they give text much of its distinctiveness. In stories, the rarer words enhance interest and understanding of characters, setting, and plot. In informational texts, the rarer words are often technical terms that give precision and clarity to the content. The extended vocabulary is often what is new for readers and increases the complexity of a text. When readers aren’t adept with the core vocabulary (i.e., the 4000 simple word families), they have few resources to deal with the new and unique vocabulary.
The core vocabulary may appear to be simpler than the extended vocabulary. That is not necessarily the case. Very complex texts can be written with the simplest of words from the core vocabulary (e.g., To be or not to be). Many words belong to the core vocabulary because of their multiple meanings and uses. For example, words such as set and back have many meanings and also take on different parts of speech.
Educators’ concerns are addressed in this issue of TextProject Answers.