Experimental Design and Hypotheses
Laboratory experiments are the gold standard in psychology research. You manipulate the independent variable (what you change), measure the dependent variable (what you're studying), and control everything else in a laboratory setting to discover cause and effect relationships.
Experimental designs come in three main types. Independent measures uses two separate groups - one does condition A, the other does condition B. Repeated measures uses the same group for both conditions. Matched pairs involves pairing up participants based on similar characteristics, then splitting the pairs between conditions.
Your hypothesis needs to be testable and measurable. A directional hypothesis predicts which way results will go, whilst a non-directional hypothesis just predicts there will be a difference. Don't forget your null hypothesis - this states there will be no effect between your variables.
Remember: All variables must be operationalised - written in a way that can actually be tested and measured!