A Level Psychology OCR Practice Exam

What is a two-tailed hypothesis primarily used for in research?

1. Predicting a specific outcome

2. Predicting an open outcome with multiple directions

3. Establishing a null hypothesis

4. Testing only one variable

The correct answer is: Predicting an open outcome with multiple directions

A two-tailed hypothesis is primarily used in research to predict an open outcome that can lead to effects in multiple directions, meaning that the researcher is interested in assessing whether a relationship exists in either direction of the tested variable. This type of hypothesis doesn’t specify a particular expected direction of the outcome, which allows for the possibility of detecting a significant effect if it exists, regardless of whether it is positive or negative. For example, if a researcher is examining the effect of a new teaching method on student performance without indicating whether performance will increase or decrease, a two-tailed hypothesis would be appropriate. It acknowledges that there could be differences in either direction, thus broadening the ability to capture the results of the research. In contrast, other options focus on more specific or limited aspects of hypothesis testing. Predicting a specific outcome would suggest a one-tailed hypothesis, which only considers changes in one direction. Establishing a null hypothesis is part of the hypothesis testing framework but does not specifically pertain to the type of hypothesis itself. Testing only one variable typically relates to a more specific situation, often involving one-tailed hypotheses rather than considering possibilities in both directions.