The teacher shows the standard method for the AQA rates of reaction required practical (sodium thiosulfate and hydrochloric acid, timing the disappearing cross) from the exam board's practical handbook. Each student posts one change they would make to that method on a class Padlet, with a one-line reason, in the column they think it belongs to: accuracy, precision, repeatability or 'changes the investigation'. As posts arrive, the teacher moves any that sit in the wrong column and asks their authors to explain what the change really improves. Students finish by writing in their books the change they now think is strongest and the term that describes what it improves.
This page is one of a growing set of PICRAT examples by cell, subject and grade. Page maintained by Andy Perryer.