Semantic or Thematic Word Clusters?
The Research
In the book No More ‘Look Up the List’ Vocabulary Instruction by Cobb & Blachowicz, the authors argue against the traditional, but ineffective practice, of teaching new words in a weekly list. Researchers have sought more efficient ways of learning - and retaining - vocabulary words.
Robert Marzano presents academic vocabulary in semantic clusters on his website MarzanoResources.com.
Elfrieda Hiebert advocates something similar in her book Teaching Words and How They Work: Small Changes for BIG Vocabulary Results and on her website textproject.org. She argues that words in the narrative genre should be taught in synonym networks while words from informational texts should be taught in topic networks.
Semantic or Thematic Clusters?
Both authors take on an approach that focuses on the relationships among words. That is, when introducing new words, students can be taught how to extend knowledge of the new word to other words. This argument for semantic clusters is appealing. The similarity of the words should ease the learning task as the student simultaneously becomes aware of the slight distinctions between the related words.
However, many researchers cite a downside to teaching words in semantic clusters as it may cause interference effects in memory: the closer two words are in meaning or association, the greater the risk of forgetting. Some studies even go as far as to suggest that semantic grouping is actually worse than presenting lists of totally unrelated words. These researchers advocate for thematic clusters over semantic clusters. While semantic clusters group words that have similar meanings, thematic clusters group words that belong to a specific knowledge schema (a set of knowledge and experiences about a topic or idea). An example of a thematic cluster would be sweatshirt, changing room, wool, salesperson.
