An environmental scientist wants to investigate whether the concentration of dissolved oxygen in a river downstream from a water treatment plant is different from the concentration of dissolved oxygen upstream. They plan to collect water samples from both locations (upstream and downstream) at identical times over a period of 20 days.
State a non-directional hypothesis for this investigation.
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.