Research methods Study Guide

In psychological research, a hypothesis is a testable statement that predicts a relationship between two or more variables. It must be clear, precise, and falsifiable, meaning it can be proven wrong through experimentation. Hypotheses are usually derived from existing theories or observations and guide the research process. For instance, a hypothesis might propose that 'students who revise using flashcards will achieve higher exam scores than those who do not'. This hypothesis identifies two key variables: revision method (flashcards vs. no flashcards) and exam scores. There are different types of hypotheses: an alternative hypothesis (H1) predicts a difference or relationship, while a null hypothesis (H0) predicts no difference or relationship. Researchers typically aim to disprove the null hypothesis to support their alternative hypothesis.

Variables are conditions or characteristics that can change or be controlled within a study. They are central to understanding cause-and-effect relationships. An independent variable (IV) is the one manipulated or changed by the researcher. In our flashcard example, the IV is the 'revision method'. A dependent variable (DV) is the one measured by the researcher; it's the outcome thought to be affected by the independent variable. In the example, the 'exam scores' would be the DV. It's crucial to operationalise variables, which means defining them in clear, measurable terms. For example, 'exam scores' could be operationalised as 'the percentage mark achieved in a 50-item multiple-choice test'. This precision allows other researchers to replicate the study and helps ensure the validity of the findings. Understanding the distinction between IV and DV is fundamental for designing experiments and interpreting results correctly.