Unlike last year, however, the optional test will take into account the disadvantages of being a summer-born child.
This year's test carries a graded chart of children's reading ages. The chart shows, for example, that a child who scores 16 out of 27 points has a reading age of six years and five months, whereas a child who gets 24 points has a reading age of seven years and 10 months.
Although the national tests are for seven-year-olds, some children are significantly younger or older than seven when they take the tests.
It is well documented that summer-born children often suffer in tests because they are younger and have spent less time in school than their classmates.
Feedback in the SCAA national curriculum review showed that teachers felt they still needed to carry out reading tests because the Government tests did not give age-adjusted scores.
A SCAA spokeswoman said: "We would like to think that we have made the test more helpful and more refined. We do recognise that one of the things some parents were unhappy about was: 'My child is not an average age'. The test places them on a national curriculum level but also enables the parent and the teacher to see how that child's performance is related to their age."
The test is not compulsory because SCAA does not want to increase teachers' workload. About 70 per cent of schools took it last year and the authority hopes that figure will increase.
It is also trying out standardised scores for seven-year-olds in mathematics and spelling in 30 schools, and is carrying out a "limited, in-depth" study on reading ages at 11.