Exercises: The steps of the scientific method

These steps of the scientific method are in the wrong order: (a) analyse data, (b) formulate a hypothesis, (c) experiment, (d) observe a striking fact, (e) draw conclusions. Put them in the correct order and write one sentence explaining what is done in each step.

Explain in your own words what a hypothesis is and write a possible hypothesis for this observation: the plants on a classroom windowsill grow leaning towards the window.

The diagram shows the steps of the scientific method, but one of them is hidden behind a question mark. Identify the missing step and explain what it involves.

A group of students observes that bread goes mouldy faster in the kitchen than in the larder. Write an investigable question about this observation, formulate a hypothesis, and express it as an "if..., then..." prediction.

To test whether light affects growth, two identical pots are prepared with the same plant, the same soil, and the same watering: one is left in the sun and the other inside a dark cupboard. Identify the independent variable, the dependent variable, and two control variables (variables kept constant), and explain what role the plant in the cupboard plays.

Explain in your own words the difference between a hypothesis, a scientific law, and a theory, and give an example of each related to falling objects.

Fewer tadpoles have been spotted in a park pond since a fountain that stirs up the water was installed. Design an experiment to test whether water movement affects tadpole development: write the hypothesis, the experimental set-up, the control group, and what you would measure.

A laboratory repeats the same experiment ten times and gets the expected result on only one occasion. Explain why the hypothesis cannot be considered proven and what the team should do next.

To prove that its new fertiliser is "the best", a company fertilises fifty pots with its product and, after a month, announces that all the plants have grown. Point out at least three flaws in the experimental design and describe how it should be done correctly.