The mathematics of vocabulary learning

2 Feb

How many words do our students need to learn? A core vocabulary of 3000 words will give a coverage of 84% of the language that a learner will meet, and this is not enough to understand much. An advanced learner will need about 7500 words (Rundell, 2010) – enough to understand 92% of the language that is met. Most learners will be aiming much lower than that, especially as a level of B1/B2 is sufficient to get through most school-leaving examinations. One way of looking at the number of words that are needed for different levels is to take the guidelines used by international publishers when they produce graded readers.

Now think how many hours of classtime you have with your students. In many contexts, it’s about 90 hours per year, but the amount of teaching time is substantially less because of testing, absences, punctuality problems, etc. And, of course, vocabulary is just one area of language learning that needs to be covered in class, often taking second place to grammar. OK, now divide the number of words that students need to acquire in a year (during which they are typically expected to move up a level) by the number of hours you have available.

Research suggests that learners, ‘as a very general average, appear to gain about four words per hour from regular classroom contact’ (Milton, 2009, p.89). Learners also need to encounter a word multiple times (research estimates vary from about 12 to 16) before they really ‘know’ it. This means that the average learner would need a minimum of 100 hours to acquire enough words to move from, say, A2 to B1. In reality, they will probably only get about half that.

The inescapable conclusion is that we do not have the time that is needed to teach the words that are needed in the classroom. These words must somehow be acquired outside the class. And that means that we, as teachers, should perhaps devote classroom time to activities that promote learning outside the classroom … rather than teaching yet another set of vocabulary.


2 Responses to “The mathematics of vocabulary learning”

  1. philipjkerr February 12, 2012 at 8:59 pm #

    Academic word list
    For students who are planning to go to university where English will be the language of instruction, it will be vital to acquire the academic vocabulary they will need to follow their courses. The Academic Word List (AWL) contains 570 word families and ‘makes up around 10% of the running words in academic text’ (Nation, 2008: p.125). It can be found here ‘The words from this list plus the most frequent 2,000 words of English cover about 90% of the running words in academic text’ (Nation, 2008: p.128). Nailing the words in this list quickly ought to be a priority for such students, and deliberate learning from lists is likely to be the best way to do it.

  2. philipjkerr May 6, 2012 at 10:11 am #

    It’s interesting to compare the rate of vocabulary acquisition of classroom learners to children learning their L1. For babies:
    18 months 50 words
    24 months 350 words
    30 months 600 words
    These figures are taken from D. Everett’s ‘Language: The Cultural Tool’, Profile Books, 2012, p.188). Classroom learners are required to make much more rapid progress than this and, unlike babies, they only have a few hours a week.

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