Not All Rare Words Are Sesquipedalian!

    by Alia Pugh and Elfrieda H. Hiebert | January 15, 2020

    A small part of the English vocabulary accounts for the majority of the words in the texts students read across the grades—2,500 word families in all. But, in any text, students can expect to encounter words that are rare in English. In a recent study, we confirmed that students can expect to see about 2.5 rare words for every 100 words they read*. The kinds of rare words differ across the texts of different grades but what is consistent across the grades from K to 12 is the presence of these rare words.  

    Rare words are often equated with multisyllabic words with obscure meanings. Some words, such as irrefragable and oriflamme are of this type (especially in high-school texts), but rare words are of a variety of types. Of the more than 14,000 individual rare words from our study, nearly one in five has five or fewer letters, and many of these short words are monosyllabic. Another pattern in our study of rare words is the presence of concrete words. Among the words in our study, more than 20% rated at least 3.5 out of 5 in concreteness. Many of these concrete words are part of thematic groups, such as animals, food, and so on.

    Students’ vocabularies can be expanded considerably when rare words are taught as part of common themes. For example, a common theme for young learners is animals, which can be divided into the sub-groups such as mammals, birds, insects, and lizards. The map below shows how some rare words from our study might be organized. Pictures can increase interest and help explain word meanings, but teachers may wish to reserve a comprehensive photo library for a paper or digital file.


    Words from various themes can be collected on word walls or in word files, taught around core concepts, and also connected with other themes (for instance, relating animal characteristics to geographic features).

    Word Pictures provides pictures for words organized around 16 themes. The Word Pictures project currently focuses on core vocabulary but rare words related to themes can be added (as the map above illustrates). In this way, students’ vocabularies are enriched and expanded. 

    *This essay is based on:

    Pugh, A., & Hiebert, E.H. (December  2019).  What is the task represented by rare vocabulary in school texts?  Presentation at the annual conference of the Literacy Research Association, Tampa, FL (available at: