Tiered words refers to the three tiers of words that we categorize according to usage. This vocabulary discussion can be linked to BICS and CALP (the use of academic language) and to the language continuum (referring to register) and also to global and local literacy (the way vocabulary can be attached to them).
Tier 1
Our first tier refers to basic words that are linked to global literacy. They are survival words and are common to all language learners. They include the pleases, thank-you’s, who, what, when, where and why words. Tier 1 words are those that are fundamental to basic communication.
Tier 2
Our second tear gives us the majority of problems for our English B students and second language learners. Tier 2 words are those high frequency words that have different meanings in different environments and subject areas. They may even have different forms (verb or noun). Some examples are:
Volume
Land
Table
Solution
Cell
Creep
Tap
Figure
Approach
React
Passive
If we consider these words carefully, we can see that they can mean many things and will vary across subject areas, something very confusing for second language learners. A good approach is to identify as many as possible. Students could probably help in the making of 2tier word lists.
Tier 2
Our third tier refers to words that are unique to only one discipline. They are part of what was described as local literacy. They are the words owned by a specific subject area. Some examples are:
Life cycle
Subtraction
Metaphor
Estuary
Genocide
Participle
Feudalism
Sanctimony
Invertebrate
Depreciation
Surgery
As these words are specific to subject areas, teachers can assist students in their acquisition by teaching them explicitly in the environments in which they occur.
Here is a helpful document to record and learn tier 2 words.
Here is a word game you can use with your students to help them learn (and teach each other) vocabulary.