Investigating the Relationship between IELTS Scores and Receptive Vocabulary Size

  • Andrew Drummond King's College London
Keywords: IELTS test, IELTS scores, EAP, vocabulary size, international foundation students


This research investigates the relationship between IELTS scores and vocabulary size, using Nation and Belgar’s (2007) Vocabulary Size Test (VST). Correlations are stated between IELTS scores and mean estimated vocabulary size for a sample of 205 international foundation students; data which may be useful for streaming within such programmes. Mean and standard deviation vocabulary size scores are given for IELTS bands: there is a wide spread of scores within each 0.5 IELTS band, highlighting the weakness of an IELTS score as a predictor of this specific area of linguistic knowledge. A model is given for ‘mean’ students at each 0.5 band of IELTS, which estimates the number of unknown words s/he may encounter in a text written for educated native speakers, given the mean vocabulary size for that band. The pedagogical implications of these results are assessed.


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Author Biography

Andrew Drummond, King's College London

Andrew is an English for Academic Purposes teacher at King's College London. He has previously taught in South Africa, Hungary and Macedonia (FYROM). His research interests include academic vocabulary, the link between vocabulary knowledge and assessment and the link between vocabulary knowledge and reading skills. Andrew can be contacted at and @drummondandrew on Twitter. There is a video presentation of the paper on his YouTube channel: