The Vocabulary of Disciplinary Texts for First Through Fifth Grade

• In Event: 29.077 - Words for Schools: A Research Project Designed to Identify the Vocabulary That Students Need to Know and Educators Need to Ensure They Learn

Abstract

Purpose

The purpose of the present study was to identify the word families, rate of introduction, and repetition that U.S. first- through fifth-grade students encounter in mathematics, science, and social studies textbooks.

Perspective

Exposure to words in domain-specific texts is likely to be especially significant because of the concept-building capacity of disciplinary materials (Adams, 2009, 2010-2011; Bravo & Cervetti, 2008). That exposure begins well before adolescence. However, disciplinary vocabulary can be abstract and conceptually dense (Nagy, Anderson, & Herman, 1987), features that can create lexical overload for students. Better understanding of the words that appear in such texts could be extremely valuable for instructional purposes. Knowledge of vocabulary features, such as rate of introduction of new words and of repetition, would be useful for practical purposes. For instance, teachers might consider more direct instruction for words that are key to domain understanding when important words are not repeated much in the text. Moreover, publishers would have a better sense of their own series’ status with regard to the challenges of helping children to develop domain-specific knowledge. To date, no frequency count of the words appearing in elementary-grades domain-specific texts exists. The present research addresses that void.

Data Sources

Based on Education Market Research (2014), four publishers’ series of first- through fifth-grade current, best-selling texts in mathematics, science, and social studies were selected.

Method

First, texts were edited and digitized. Next, for the main analysis, to identify word families, computer-based morphological analysis was accomplished using Morfessor (Virpioja, Smit, Grönroos, & Kurimo, 2013). Reliability of Morfessor with a digital dictionary (Celex2 [Baayen, Piepenbrock, & Gulikers, 1995]) was 93%. Then, as word families were identified, the “level” of each word family was determined following the analysis of Bauer and Nation (1993): Level 1—every word form counted (no families); Level 2—root words and their inflected forms; Level 3—root words with most common derivational affixes; and Level 4—classical roots and classical affixes. Finally, a wide variety of descriptive statistics was calculated by grade within each discipline.

Results

Main findings were as follows: a) Mathematics texts led domains in percentage of new word families. New word families were introduced more rapidly than in the other domains and repeated less frequently. b) For all three domains, some word families occurred with a great deal of frequency (e.g., observe, discover). However, beyond that foundational set, many word families were introduced but infrequently repeated. c) For all three domains, surprisingly little “spiraling” (expansion of concepts introduced earlier) of word families occurred across grades.

Scientific Significance

Knowing disciplinary vocabulary isn’t just about knowing words. It’s about connecting and understanding webs of concepts. To gain breadth and depth of disciplinary knowledge, students must gain control over domain-specific vocabulary (Adams, 2010-1011; Armbruster, 1992; Schleppegrell, 2007). With recent renewed emphasis on the integration of literacy in the content areas in the CCSS, including the elementary grades (Moss, 2011), better understanding of the disciplinary vocabulary in texts is an essential foundation for enhanced instruction.

Author

• Jill Fitzgerald, UNC at Chapel Hill and MetaMetrics