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Data analysis: hypothesis testing
Data analysis: hypothesis testing

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4.4 Check your understanding

In the following activity, you will be tested on your understanding of one-tailed and two-tailed tests with respect to a bell-shaped curve.

Activity 4 One-tailed or two-tailed test

Timing: Allow approximately 10 minutes to complete this activity

Can you match the statements with the bell curves that indicate either a one-tailed or two-tailed test?

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In conclusion, the choice between a one-tailed test and a two-tailed test (as well as between a directional and non-directional hypothesis) depends on the research question and the nature of the relationship or difference being studied. Two-tailed tests and non-directional hypotheses are useful when the research question is exploratory, or the direction of the relationship is unknown, while one-tailed tests and directional hypotheses are useful when a specific direction of the relationship or difference is predicted and is of interest. Careful consideration and planning are necessary when choosing between these options to ensure that the hypothesis is properly tested and the correct conclusions are drawn from the data. Ultimately, the choice of the type of test and hypothesis should be guided by the research question, the theory behind the study, and the available data.