An agricultural scientist is conducting an investigation into the effect of a new organic fertilizer on the average crop yield of heirloom tomato plants. Since extensive pilot studies and established botanical theory indicate that this fertilizer increases crop yield, the scientist formulates a directional hypothesis.
Explain why a directional hypothesis is appropriate for this study.
689 exam-style questions on AQA A Level Psychology Scientific processes. Each one has a worked solution and a mark scheme showing where the marks go.