Every score mockDe gives you is derived from the official IELTS band descriptor framework published by Cambridge Assessment English. This page explains exactly how our AI examiner works, how accurate it is, and where it has known limitations - so you can decide how much to trust each score.
Each criterion is weighted equally (25%). The four sub-scores are averaged and rounded to the nearest 0.5 to give the module band score - exactly as in the official exam.
Task Achievement (TA)
Weight: 25%Does the response fully address all parts of the task? Does it present a clear position throughout? Are ideas extended and supported?
Cambridge Assessment English Band Descriptors for Writing Task 2Coherence & Cohesion (CC)
Weight: 25%Is information and ideas organised logically? Are cohesive devices used accurately and with appropriate flexibility?
Official IELTS Band DescriptorsLexical Resource (LR)
Weight: 25%Is there a wide range of vocabulary used with flexibility and precision? Are less common items used with awareness of collocation?
Official IELTS Band DescriptorsGrammatical Range & Accuracy (GRA)
Weight: 25%Is there a wide range of structures used with flexibility and accuracy? Are errors rare and only minor?
Official IELTS Band DescriptorsEach criterion is weighted equally (25%). The four sub-scores are averaged and rounded to the nearest 0.5 to give the module band score - exactly as in the official exam.
Fluency & Coherence (FC)
Weight: 25%Does the candidate speak at length without noticeable effort? Is speech coherent and is the production of speech appropriate?
Official IELTS Speaking Band DescriptorsLexical Resource (LR)
Weight: 25%Is vocabulary used flexibly and precisely? Can the candidate discuss a variety of topics using paraphrase effectively?
Official IELTS Speaking Band DescriptorsGrammatical Range & Accuracy (GRA)
Weight: 25%Is there a mix of simple and complex structures? Are errors rare and do they rarely reduce communication?
Official IELTS Speaking Band DescriptorsPronunciation (P)
Weight: 25%Is the accent easy to understand? Are features of connected speech used to aid clarity? Is intonation natural?
Official IELTS Speaking Band DescriptorsThe Overall Band Score is the average of the four module scores (Listening, Reading, Writing, Speaking), rounded to the nearest whole or half band using Cambridge's published rounding rules:
This is the same calculation used by IDP, British Council, and all authorised IELTS testing centres globally. mockDe applies it identically.
We believe transparency about limitations is part of being a trustworthy tool. Here is where our scoring is imperfect.
AI Speaking scores can vary ±0.5 bands from official
Our Speaking AI evaluates transcribed audio, not raw audio waveforms. Pronunciation scoring is the weakest criterion because subtle accent and intonation features are harder to capture via transcript alone. Treat Speaking band predictions as directional, not definitive. For visa-critical scores, always sit an official IDP or British Council exam.
Writing scores are calibrated to Band 6.0–8.0 accuracy
Our Writing AI is most accurate in the Band 6.0–8.0 range - the range where 85% of IELTS candidates sit. Scores below Band 5.5 and above Band 8.5 are less reliable because training data at these extremes is sparse. Band 9.0 predictions are disabled intentionally.
No penalty for use of Indian English conventions
IELTS officially accepts any accent and any national variety of English. Our AI is trained to not penalise Indian English spelling variants (e.g., 'colour' vs 'color'), Indian formal register conventions, or Indian English collocations that are valid in the regional variety.
Reading and Listening are objectively scored
Reading and Listening are multiple-choice / short-answer formats with definitive correct answers. Our scores for these modules are exact - there is no subjectivity or AI inference involved. We use the official IELTS raw score to band score conversion tables published by Cambridge Assessment English.
Mock test questions are not official IELTS questions
mockDe mock test questions are original content written to mirror official IELTS difficulty and format. They are not leaked or licensed IELTS questions. Passage difficulty, question type distribution, and timing are calibrated against the official IELTS practice materials published by Cambridge.
IELTS Scoring in Detail
IELTS.org (Cambridge + IDP + British Council)
Official band descriptors for all four modules
IELTS Band Descriptors (Writing Task 2)
Cambridge Assessment English
The full marking criteria document used by all official examiners
IELTS Speaking Band Descriptors
Cambridge Assessment English
The four Speaking criteria with level descriptors for each band
Understand Your IELTS Results
British Council
Official explanation of how the Overall Band Score is calculated
IDP IELTS Score Guide
IDP Education
Band score descriptions and what each level means for real-world language use