Why I did this study:

It is generally agreed that vocabulary knowledge plays a crucial role in reading comprehension. It would be hard to understand any text or content without understanding the individual words making up the text. Vocabulary knowledge, therefore, is critical in the language acquisition process and creates a positive feedback loop: more vocabulary knowledge leads to better reading comprehension, and more reading provides more opportunities for learning new words and phrases.

Vocabulary knowledge is often thought of as the command of individual words. However, we often group words to form non-literal or figurative meanings. These phrases are referred to as idioms. For example, ‘kick the bucket’ is an idiom because it usually does not mean literally to kick a bucket. Instead it has a figurative meaning: ‘to die’. In what follows, I will use the term ‘idiomaticity’ to describe groups of words like these.

Few researchers have studied the relationship between idioms and reading comprehension because we usually think of vocabulary knowledge as knowing the meanings of individual words. However, idioms pose difficulties to reading comprehension for several reasons. First, learners are often unaware of their presence because there are no clear boundaries for idiomatic phrases, such as spaces or punctuations. Second, learners often attempt to interpret their meanings literally and so get confused.

My study was set in China. Here, English is most commonly taught as an academic subject (i.e English as a Foreign Language, or EFL), and vocabulary tends to be taught through rote memorisation of individual words. Despite years of formal English education in this way, Chinese students often do not achieve as highly as one might expect. A more recent development in China is the provision of English immersion programmes, where learners study academic subjects (e.g. Maths and Science) in English. Immersion programmes are based on the belief that through immersing learners in English as much as possible, they can gradually learn to use the language more effectively.

In the light of these issues, I developed the following two aims. The first was to understand whether idiomaticity affects how well Chinese adolescent learners of English understand what they read in English. The second was to see how well learners in English immersion schools understand what they read compared to learners studying EFL.

What I did:

I recruited students from aged 15 to 16 from two classes in the same school. One class was a traditional EFL class, the other was part of an immersion programme. Students in the EFL class followed a programme of one English lesson (40 minutes) a day, while students of the EI programme learned all of their academic subjects in English.

I asked students to complete three tests. The first was a set of two reading comprehension tasks. In each task students read a passage of writing then were asked to say how well they thought that they understood it. The two passages contained similar sets of words, but one included more idiomatic expressions. They then answer comprehension questions on each passage. The second task was a vocabulary test measuring students’ vocabulary size. The final task was a non-verbal IQ test, which I used to confirm that each class was similar in terms of their IQ.

What I found:

In general, students scored lower on the reading comprehension test when the passage contained idioms. In addition, according to the self-reported comprehension scores, most students were aware that they had more difficulty with the passage containing idioms.

Regarding the relationship between vocabulary and reading comprehension, learners’ vocabulary size positively correlated with their performance on the reading comprehension test containing idioms. That is, the bigger the vocabulary size of the student, the better they tended to do on the comprehension test.

Learners did not perform as well on the reading comprehension test with more idiomaticity, suggesting that idiomaticity in written texts created difficulties for their reading comprehension. In other words, idioms make passages harder to comprehend. The result of self-reported comprehension scores showed that learners, to some extent, were aware of these difficulties. However, they were not able to identify all the idioms, which led them to overestimate how well they understood the passages containing idioms.

Despite the general trend found in both EFL and EI groups, there were a few significant differences in students’ performance between the two groups. In particular, EFL learners performed better than EI learners on the two reading tests. EFL learners were also more accurate in their self-assessment.

When comparing the performance between EFL and EI learners, I found that, contrary to the popular belief that immersion is an efficient way to learn a language, EFL learners scored higher in both reading comprehension and were more accurate in their self-reported scores. My research suggests that teaching idioms explicitly, as it tended to happen in the EFL classrooms, may be more beneficial.

What it means:

For teachers, this research suggests that teaching idioms explicitly as part of general vocabulary instruction may be beneficial. Because learners may not be aware of the presence of idioms nor what they mean, strategies focusing on these features of English may improve reading comprehension for Chinese learners of English in both EFL and immersion programmes.

Christine’s dissertation “Effects of Frequency and Idiomaticity on the English L2 Reading Comprehension of Secondary School Students in China”, on which this blog post is based, is available via the Bodleian Library, see here.