
Academic Writing Task 1
Grading
Included in the instruction is “You should spend about 20 minutes on this task.” This is just some friendly advice from IELTS and not one of their regulations so the test invigilators will not stop you after 20 minutes and order you to start task 2.
Unfortunately, some candidates sometimes spend too much time on task 1 which means that task 2 is rushed. There is also no IELTS regulation stating that you must do the tasks in order. So, if you want to start with task 2, that’s fine.
Try to aim for 150 – 170 words in Academic task 1 and keep in mind that even though there is no IELTS restriction on the number of words you can write (tasks 1 and 2), writing 200 + words on Task 1, it is really not necessary and is not effective time management.
Some candidates ask if there is a penalty for writing too many words... there isn’t.
However, answers under the word count are penalized in the Task Achievement criterion. When the examiner sees that your answer is short, they will count the number of words and must follow the IELTS rules for word count.

The examiner will give you a band score in Task Achievement and then minus that score according to the number of words. Click on the following link for how words are counted in IELTS writing...
Scoring
Task 1 is worth 33% of your overall writing band score.

You are graded in 4 criteria – Task Achievement, Coherence and Cohesion, Lexical Resource and Grammatical range & accuracy.
Click on the PDF link to view the official IELTS band descriptors (public version). Contrary to some IELTS myths about a hidden set of band descriptors for examiners’ use, you are graded on these alone.
The criteria are equally weighted with 25% awarded for each category and the writing band score is the average of the four. For example…

If you want to calculate your overall band score…

Task Achievement
This measures how well you address the requirements of the task. The descriptors mention "key features may be inaccurate/irrelevant". This is the wrong reporting of data and/or giving opinion, reasons, explanations for the information in the diagram.
Example:
The USA won the highest number of gold medals with a total of 46 because they have the best athletes and training programs.
DON’T give your opinion or reasons/explanations for the information in the diagram. Task 1 is an objective report and not an essay. State the facts only and study the data carefully. Your score in task achievement will depend on how often you include irrelevant information and/or report innacurate data.
Band 4: key features may be inaccurate/irrelevant
Band 7: Content is accurate & relevant but may be few lapses
Task Achievement also mention...
Band 5: recounts details mechanically
This is when students try to describe every feature in the diagram.
Trying to describe every feature in the diagram is too time consuming and will require a lot more than 150 words. Only describe the key features and make comparisons.
Band 5: no data to support the description
Example:
A. The USA won the highest number of gold medals.
B. The USA won the highest number of gold medals with a total of 46.
Sentence A has no data while sentence B includes the data (the number). Every description of the key features must include the data (figures). Follow the link for how to describe the key features.
Academic Writing Task 1: Main Features & Comparisons
Also included is...
Band 5: no clear overview
The introduction for Academic task 1 must have an overview. That is, a summary of the information in the diagram. Follow the link for how to write a clear overview.
Academic Writing Task 1: Introduction - Paraphrase & Overview
Format is also in the task achievement criterion. This is organizing your report into paragraphs and written in formal style. Your score ranges from Band 4 to 7.
Band 4: Format may be inappropriate
Band 7: Format is appropriate
Click on the link for tips on how to structure your report.
Coherence and Cohesion
The Coherence and cohesion criterion is exactly the same for General Training and Academic tasks 1 and task 2.
Click on the following link for detailed a discussion of Coherence and cohesion...
IELTS Writing: Coherence & Cohesion
Click on the following link for a list of cohesive devices...
Lexical Resource
Lexical resource is the range of your vocabulary, your awareness of style and collocation and spelling ability.
For a more detailed discussion and tips for Lexical resource, click on...
Grammatical Range and Accuracy
The Grammatical range and accuracy criterion is exactly the same for General Training and Academic tasks 1 and task 2.
Click on the following link for a detailed discussion of Grammatical Range and Accuracy.