Table 3.
Various estimates of the number of English words known by adults (typically first-year university students), together with the way in which “words” were defined and the task used.
| Study | Estimate | Definition of “word” | Task |
|---|---|---|---|
| Hartmann (1946) | 215,000 | All entries from Webster’s New International Dictionary | Meaning production |
| Nusbaum et al. (1984) | 14,400 | Lemmas present both in Miriam-Webster’s Pocket Dictionary and Webster’s Seventh Collegiate Dictionary (list of 19,750 words) | Familiarity rating |
| Goulden et al. (1990) | 17,200 | Base words (sic) from Webster’s Third New International Dictionary, excluding proper nouns, derived words, and compounds. | Indicate whether word is known or not |
| D’Anna et al. (1991) | 17,000 | Functionally important lemmas (sic) from the Oxford American Dictionary, with the exception of abbreviations, hyphenated words, affixes, contractions, interjections, letters, multiword entries, slang, capitalized entries, foreign words, alternate spellings, and outdated words. | Subjective estimates of knowledge |
| Anderson and Nagy (1993) | 40,000 | Distinct lemmas (sic) from a corpus based on school textbooks; excludes proper nouns and a limited number of very transparent derived words and compounds. | Various tests |
| Zechmeister et al. (1995) | 12,000 | Same as in D’Anna et al. (1991) | Multiple choice questions related to the meaning of the words |
| Milton and Treffers-Daller (2013) | 9,800 | Same as in Goulden et al. (1990) | Provide synonym or explanation for words known |