Which vocabulary tier consists of words not frequently used, except in specific content areas?

The vocabulary tier that consists of words not frequently used outside of specific content areas is Tier Three Vocabulary. This tier is characterized by specialized terminology that is often limited to particular subjects or fields, such as scientific, technical, or academic language. For example, terms like "photosynthesis" in biology or "gerrymandering" in political science would be categorized as Tier Three, as they are primarily used in specific contexts and may not be widely known or used in everyday conversation.

In contrast, Tier One vocabulary includes basic words that are commonly used in everyday language, while Tier Two consists of more sophisticated words that may be used across multiple contexts but are still fairly common. Common Vocabulary is not an officially recognized tier in this context, but rather a general way to describe words that people frequently encounter in daily communication. Understanding these tiers helps educators focus on vocabulary instruction by differentiating between the levels of complexity and usage of words in language learning.