P5.1—Defining the problem and prediction

A plan begins with a testable prediction, named independent and dependent variables and the key variables to standardise.

Link the prediction to a biological mechanism and make the expected direction or pattern explicit.

If increasing light is predicted to increase photosynthetic rate until saturation, the prediction identifies both the trend and its limit.

A vague aim such as “investigate photosynthesis” is not a testable prediction.