Vocabulary use in the FCE Listening test - Cambridge English Exams

4 | CAMBRIDGE ESOL : RESEARCH NOTES : ISSUE 32 / MAY 2008Figure 1: Extract from Costa RicaRight now there’s a big problem with deforestation in Costa Ricaand one of the things that we need to do is to provide educationand we have a great opportunity here. We’ve got an educationprogramme in place where we will bring students in, free ofcharge and tell them about er the canopy and why it should besaved…Figure 2: Extract from Cable Car… need to do to stop that is to provide education. We’ve got aprogramme in place where we will bring students in from all overthe world and tell them about the forest and they can see forthemselves why it should be saved.Creating word frequency listsWordlists were made by running the two corpora throughWordSmith Tools (Stubbs 1996). The resulting exam textswordlist and radio texts wordlist were compared topublished British National Corpus (BNC) lists for spokenand written language (Leech, Rayson, Wilson 2001).The wordlists were then used to make key word lists inWordSmith Tools, using the larger composite radio text as areference text. The KeyWord tool finds words which aresignificantly more frequent in one text than another. If aword is unusually infrequent in the smaller corpus (theexam texts here), it is said to be a negative key word andwill appear at the end of the list.Concordances were then run on selected words, so thattheir usage in both sets of texts could be studied in moredetail.Results: lexical densityAs can be seen from Figure 3, all texts ranged from 30% to44% lexical density. This is lower at the bottom and top ofthe range than Stubbs’ (1996) finding for spoken texts(34% to 58%). At the upper end, this difference can beaccounted for, as most of the texts studied here aredialogues and would not be expected to have particularlyhigh lexical densities. The presence of results which arelower than 34% could, however, suggest that the methodfor calculating lexical density used in this study createddifferent results from Stubbs’ method.None of the texts analysed, whether exam or radio texts,have a lexical density greater than 44%, even though someof them are monologues where there is no feedback. Thiswould suggest that all these radio texts are dialogic in someway, with speakers regarding the listeners as involved inthe interaction to some extent, even though there is nooption for actual feedback.It is hard to see a particular pattern when comparing theexam texts to the radio texts; some exam texts have higherlexical density than the corresponding radio texts (fivetexts) and some radio texts have higher lexical density thanexam texts (four texts). Overall though, the exam texts havea slightly higher lexical density. The average is 37.5% asopposed to 36.8% for the radio texts.An independent t-test for significance was carried outusing SPSS©. There was no significant difference foundbetween the conditions (t=.443, df= 16, p=.663, twotailed). This shows that the difference between the meanlexical densities of the exam texts and the radio texts is notsignificant to 95% probability. That is to say, it isreasonable to assume that the differences in mean areattributable to chance.What is noticeable, however, is the range of densities inthe texts. The difference between the highest and lowestdensities on the radio texts is 13.5%. On the exam textsthis difference is only 6.5%, so it seems there is a tendencyfor the radio texts to have more variation in lexical densityand the exam texts to conform to an average density.Results: word frequencyTable 2 shows the top 50 words in radio texts, exam textsand, for comparison, the BNC spoken corpus and BNCwritten corpus.Figure 3:Lexical density of radioand exam textsPercentage lexical density45.0040.0035.0030.00Exam textRadio text25.0020.00Urban WildlifeJanet EllisCosta RicaJames DysonParakeetsPatricia RoutledgeVictoria BeckhamBonesLara HartTexts©UCLES 2008 – The contents of this publication may not be reproduced without the written permission of the copyright holder.