Let us analyze the IELTS writing task 1 response of a candidate who was preparing for IELTS Academic exam.
The bar chart depicts marriage and divorce rates in the USA for the years 1970, 1980, 1990 and 2000. This is accompanied by an another bar chart illustrating percentage of American adults who were married, never married, widowed and divorced in the years 1970 and 2000.

As it can be seen from the bar chart, in the year 1970 there were 2.5 million marriages and 1 million divorced people in the USA. In the next decade, total number of married people remained the same as in the previous decade, however, the divorce rates were increased by 0.4 million compared to 1970. In the year 1990, marriages decreased in number by 0.25 million in comparison to last two consecutive decades, likewise, divorce rates also dropped down to just above 1 million as compared to 1.4 millions in 1980. In 2000, there were 2 million married and 1 million divorced people in the USA

In 1970, 70% of adults were married, 12% of the total adults, never married and 5% of widowed adults were present and very negligible percentage of adults were divorced. On the other hand in 2000, married population dipped by 10% in addition, 20% of adults never married and nearly 20% of divorced in 2000 as compared to the year 1970.

Overall, percentage of married people decreased since 1970 and percentage of unmarried increased by the 20^th century. However, divorce rates remained fairly stable for the period in question.

Now, let us find out the strengths and areas of imrpovement to decide the overall band score for the above IELTS writing task 1 response.

Introduction

Strength:

The main feature of the question is well explained which provides good introduction to the problem statement.

Corrected Erroneous Statement:

None

Body Para 1

Strength:

Main key features are explained, sentence connector is used and complex structures are used.

Corrected Erroneous Statement:

“in the year 1970 there were” should be “in the year 1970, there were”, “comparison to last two” can be “comparison to the last two”

Body Para 2

Strength:

Sentence connector (on the other hand) is used and main key features are again highlighted well

Corrected Erroneous Statement:

“12% of the total adults, never married” should be “12% of the total adults were never married”, “5% of widowed adults were present” should be “5% of adults were widowed”

Last statement can be:

“On the other hand in 2000, married population dipped by 10%. In addition, 20% of adults were never married and nearly 20% were divorced in 2000 as compared to the year 1970.”

Conclusion:

Strength:

Sentence connector (overall) is used and general idea of the question is explained.

Corrected Erroneous Statement:

“for the period in question” can better in written with exact period of figures

Expected Band Score: Band 6.5

The candidate, though mostly writes free from grammar and tense errors, but there are a few noticeable mistakes related to forming passive sentences, punctuation and others.