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Vocabulary A-Z Tiering System

Research-Based Categorization

The tiering system uses established research and qualitative analysis to categorize words based on the following criteria:

Tier 1

Basic words that children typically learn before starting school. For example, cat is a Tier One word because it's easy, short, and common. Some other Tier One words are run, air, and slow. These words serve as a foundation for more challenging vocabulary.

Tier 2

Words students typically learn during schooling. Tier Two words are common words for mature language-users that are central to academic reading and writing. For example, primary is a Tier Two word because it's more challenging, but it's also frequently used and not limited to specific contexts. Students will often be able to describe Tier Two words using words they already know. Tier Two words also provide specificity and nuance.

Tier 3

Less common words students typically learn for a specific field of study or content area. For example, estuary, monochromatic, and euphemism are all Tier Three words because they refer to specialized knowledge domains. These words are not used widely across topics. Tier Three also includes archaic or obsolete words.


Beck, Isabel L., Linda Kucan, and Margaret G. McKeown. Bringing Words to Life. New York NY: Guilford Press, 2013.
Beck, Isabel L., and Margaret G. McKeown. "Teaching Vocabulary: Making the Instruction Fit the Goal." Educational Perspectives, 23 (1), (1985), 11-15.
Marzano, Robert J. Building Background Knowledge for Academic Achievement: Research on What Works in Schools. Alexandria, VA: ACSD, 2004.
Marzano, Robert J. Teaching Basic and Advanced Vocabulary: A Framework for Direct Instruction. Boston, MA: Heinle Cengage, 2010.