Understanding Hypotheses and Variables

What is a hypothesis in scientific research?

• A random guess about the outcome of an experiment

• A testable statement predicting the relationship between variables

• A detailed description of the experimental procedure

• A summary of the results of an experiment

Which of the following is an example of a well-formulated hypothesis?

• Plants need water to grow.

• If plants are given more sunlight, then they will grow taller.

• Plants are green.

• Plants grow in soil.

What is the independent variable in an experiment?

• The variable that is measured

• The variable that is kept constant

• The variable that is changed or controlled

• The variable that is not used

In an experiment to test the effect of temperature on the solubility of sugar in water, what is the dependent variable?

• The amount of sugar

• The temperature of the water

• The solubility of sugar

• The type of sugar

Which of the following is a controlled variable in an experiment?

• The variable that is changed

• The variable that is measured

• The variable that is kept the same throughout the experiment

• The variable that is not important

Why is it important to control variables in an experiment?

• To make the experiment more complicated

• To ensure that the results are due to the independent variable

• To make the experiment easier to conduct

• To increase the number of variables

What is the purpose of a control group in an experiment?

• To provide a standard for comparison

• To introduce new variables

• To confuse the results

• To increase the sample size

Which of the following is an example of a quantitative observation?

• The liquid is blue.

• The liquid has a sweet smell.

• The liquid has a volume of 250 millilitres.

• The liquid is in a glass beaker.

In an experiment, what is the role of the dependent variable?

• It is the variable that is changed by the experimenter.

• It is the variable that is measured or observed.

• It is the variable that is kept constant.

• It is the variable that is not used.

What is the first step in designing an experiment?

• Collecting data

• Formulating a hypothesis

• Analysing results

• Drawing conclusions