a test of lexico-grammatical knowledge: this is generally recognised as the test type which is most predictive of general ability, as well as being relatively practical to administer
a test of reading proficiency: this is generally considered to be the type of test next most predictive of general ability, after the lexico-grammatical
benchmarking to international standard specifications such as those in the Common European Framework, probably at levels A1, A2 and B1 for the first test, and then extended to B2 also if a repeat test is carried out in the coming years.