How we develop the test
The IELTS test is developed to provide a fair, accurate and reliable assessment of English language proficiency
IELTS has rigorous test design, development and validation processes. These processes ensure that every version of the test is of a comparable level of difficulty, and that every test around the world provides valid and consistent results.
Test writers from different English-speaking countries develop IELTS content so it reflects real-life situations around the world and is unbiased and fair to all test takers, whatever their background.
Stages of test development
Teams of language specialists based in Australia, Canada, New Zealand, the UK and the USA are regularly commissioned to write test questions. The writers work from test specifications that detail the characteristics of the four IELTS components, and outline specific requirements. They also guide writers on how to approach the item writing process, including the selection of appropriate material and the development of suitable questions.
Pre-editing is the first stage of the editing process and takes place when commissioned materials are initially submitted by item writers. It ensures that submitted material conforms to the specifications in every respect (e.g. topic, level of language, style of writing, level of task, focus of task). At this stage, guidance on the revision of materials for resubmission is provided to the item writers.
Based on pre-editing feedback, materials are revised and submitted for editing. Materials are then approved for pretesting or are sent back to a writer for further revision.
New materials are pretested on representative groups of test takers from around the world who are preparing to take an IELTS test. The Validation and Data Services team at Cambridge Assessment English collates and analyses resulting data to determine how difficult the items are, and how well they distinguish between stronger and weaker test takers. They can then make informed decisions on whether materials can be accepted for use in IELTS tests.
Standards fixing involves the testing new Listening or Reading materials with representative groups of test takers. The aim is to gauge the difficulty of new Listening and Reading tests in order to ensure that band scores on every version of the IELTS Listening and Reading tests indicate the same measure of ability. Following standards fixing, the new materials are ready to be used in live tests.
Papers are constructed for all four test components according to established principles. Among the factors taken into account are:
- mean difficulty of the test version and the range of individual item difficulties
- range of language skills tested
- balance of task types
- balance of topic and genre
- range of cultural perspectives
- range of voices and accents in the Listening versions.
Calculating the overall band score
A score is given for each test component – Listening, Reading, Writing and Speaking. These individual scores are then averaged and rounded to produce an overall band score.
IELTS results validity period
While it is up to each organisation to set a validity period that works for their purposes, the IELTS partners recommend a 2-year validity period for IELTS test results based upon the well-documented phenomenon of second language loss or 'attrition’.