Reading comprehension is weak across several classes taught by different teachers. Before launching a school-wide intervention, the headteacher should first:

Correct answer: analyse common instructional causes across the classes Analysing common instructional causes across the classes diagnoses the problem before an intervention is chosen.

• arrange a general workshop before diagnosing the difficulty A general workshop before diagnosis may miss the real causes.
• purchase a new reading programme immediately Buying a programme immediately assumes a solution without a diagnosis.
• increase testing of low-performing learners first More testing of low performers measures the problem but does not explain its cause.