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IELTS Score Gains: Findings from Research

Updated: Jun 12, 2021

Summary by Linh Phung

Note: Please cite this article and the original article if you use this summary as is. You can also share the link to this summary. The full report is posted in the reference section at the end of this article.


How long does it take to improve the IELTS band score? How much study time is needed? Is it effective to enroll in an IELTS course? Is it correct that students can improve a few bands within a few months? These are some common questions from parents, students, and teachers who are interested in the IELTS test. I’d like to summarize some findings from a report of a research project funded by British Council, Cambridge Assessment English, and IDP (Ahn, Yaw & Chung, 2021). Before sharing the findings, I’d like to give some background information about the IETLS exam. In addition, please note that these are findings from a research study in a particular context, so readers need to be cautious in applying the findings to their context.

General information:

The IELTS exam was designed to measure the English proficiency of non-native speakers of English who mostly take the test to immigrate to another country or to study at a tertiary institution. The overall band score of the IELTS test ranges from 0 to 9. Colleges and universities in the world generally require a minimum of 6 or 6.5 for undergraduate study and 7.0 for graduate study. There are four components in the test: Listening, Reading, Writing, and Speaking.


The study examined IELTS score gains among 52 Korean students enrolled in a 12-week IELTS preparation course in South Korea and the relationships between the score gains and (1) the number of hours of study, (2) the amount of target language use, (3) students’ proficiency level, and (4) some other factors.

The students took an IELTS course that met 4 hours (or 200 instructional minutes) a day from Monday to Friday or 90 minutes per day from Monday to Friday. Apart from spending time in class, they studied on their own and used English for other purposes in their own time. They took an official IELTS test before the course (pretest) and after the course (posttest). Below are the major findings.

1. The average IELTS band gain was .30. The range of the band gains was -1 to 1.0. The most improvements were in the writing score with an average gain of .46 followed by listening (.31) and reading (.23). The gain in speaking was not significant.

2. More students at a lower proficiency level (pretest scores between 4.0-6.0) made better gains than students at the higher proficiency level (pretest scores of 6.5-7.5). Statistical tests also showed that proficiency was negatively correlated with the band gains (r = -.490). One explanation is that it is more difficult and takes longer than 12 weeks to boost one's English proficiency at the higher level.

3. On average, students spent 284.38 hours over the period of 12 weeks (an average of 23.7 hours a week) to study English (attending lessons and doing extra work) with one student spending 720 hours. This student gained 1.0 band in the posttest. This amount of study time was positively and moderately correlated with IELTS band gains (r = .434).

4. On average, students spent 272.80 hours using the target language (watching TV, using social media, and talking to others) over 12 weeks (an average of 22.7 hours a week). This amount of language use was not significantly correlated with IELTS band gains (p = .135).

Further analyses into other factors that correlated with IELTS band gains showed that:

5. Program attendance (attending lessons) was slightly correlated (r = .328).

6. Perceived progress in English and IELTS (students’ feeling that they made progress) was moderately correlated (r = .403).

7. Instrumental motivation (e.g. parents’ suggestion, job requirement, future study plan, and self-achievement) was slightly correlated with IELTS band gains (r = .354).

The researchers acknowledged other random variables not examined here.


Overall, the study indicates that it is possible to improve one’s IELTS score within 12 weeks, and the amount of time invested in studying is a very important predictor. Note that in this study, the participants spent over 45 hours a week to study for the IELTS and use English. Many of them commented that this amount was not enough. They thought they should spend over 70 hours a week studying. In addition, students at a lower proficiency level (4.0-6.0) are more likely to improve their band score than students at a higher level (6.5-7.5). It generally takes more time to improve one's proficiency at a higher level.

Final thoughts:

Through this summary, I'd like to encourage students and parents to have realistic expectations about IELTS score gains. Students may spend time developing their general English proficiency, and when they are ready, they can take an IELTS preparation course to boost their score. In addition, language proficiency is more than having a high IELTS score, so the efforts you spend on using and developing your English always mean something even when the score does not immediately improve.


Kang, O., Ahn, H., Yaw, K., and Chung, S-Y. (2021.) Investigation of relationships between learner background, linguistic progression, and score gain on IELTS, IELTS Research Reports Online Series, No. 1. British Council, Cambridge Assessment English and IDP: IELTS Australia. Available at

Summary in Vietnamese is HERE.


Note: Eduling International Academy offers IELTS courses to develop students' general language skills and test-taking strategies. Check our information:

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