A total of 1.8 million children will write 7.2 million scripts in the third year of national curriculum tests for seven, 11 and 14-year-olds this month.
There are few major changes to the tests but this is an important year because education advisers will be able to chart pupils' progress over three years.
David Hawker, an assistant chief executive specialising in testing at the School Curriculum and Assessment Authority, said: "We will have very high quality data on national performance and schools will have that as well. They will start to identify trends in performance."
Minor changes to the tests include a reading comprehension for seven-year-olds at level 2; the reinstatement of a separate report on children's spelling; a paper without calculators for the maths test for 14-year-olds; improvements to the presentation and clarity of the mark scheme; and improvements to the wording of questions.
Mr Hawker said: "One of the great scandals of this country is secondary schools not making proper use of the key stage 2 test results. Secondary heads say they can't use them. We are promoting software which will help them to transfer records in a standard format."
The authority is also conducting two pilots on grammar, spelling and punctuation for 14-year-olds, and mental arithmetic for 11 to 14-year-olds. New national tests on these subjects may be set next year.
Two of the harder questions in the mental arithmetic pilot for 14-year-olds are: "What is the cost of four pictures at Pounds 2.99 each?" and "Pat cycles 10 kilometres in 40 minutes. What is Pat's average speed in kilometres per hour?" Pupils may not show any working out on paper.
In the English pilot, 14-year-olds are given the opening of a detective story and asked to find adverbs, adverbial phrases, the subjects of two verbs, and subordinate clauses.
Inexpensive software has been developed to analyse pupils' performance. Schools can record pupils' answers to all the questions in the tests on a machine called an optical mark reader. The machine analyses the results and produces profiles of the pupils' performance on each question.
Valuable information can be sought from "clusters". For example, if a significant number of students have all got a hard question right or an easy question wrong, the analysis could tell the school something about the quality or effectiveness of teaching at their schools.