A cross-party group of MSPs is to hold an inquiry into standardised assessments in Scotland's schools.
The education and skills committee will explore why the Scottish government introduced them, and whether they can close the attainment gap.
It is separate to the independent review into Primary (P)1 assessments.
Standardised testing is currently carried out in P1, P4, P7 and Secondary (S)3. The MSPs will also look at what happens in other countries.
The committee will investigate the evidence base for moving away from the previous Scottish Survey of Literacy and Numeracy, which was discontinued in 2016.
Under that system, national performance in literacy and numeracy was measured in alternate years, and the first level was assessed near the end of P4. There were further assessments in P7 and S2.
Reduced to tears
Ministers said the new standardised assessment scheme would provide more information about a child's progress.
However, it has been controversial, with some teachers claiming children have been reduced to tears by the tests.
Last month, Education Secretary John Swinney announced an independent review of testing for P1 pupils, after Holyrood voted against including younger children in the programme.
At the time he pledged this review would be "led by the evidence" and could conclude the testing regime should be reformed or scrapped altogether.
Convener Clare Adamson stressed the education committee's inquiry was not seeking to duplicate the review of P1 testing.
She said: "Instead, this inquiry will be an open and transparent look at the evidence base for using standardised assessments across primary and secondary schools.
"We want to find out what role these play in Scotland's schools. And, more importantly, how these will help to improve the educational outcomes for young people across the country."