experi method

• An aim is a general expression of what the researcher intends to investigate
• A hypothesis is a statement of what the researcher believes is true. It should be operationalised (clearly defined and measureable)
• A directional hypothesis states the direction of an experiment e.g. there is going to be a greater correlation
• Non-directional hypothesis doesn't state the direction, just that there is a difference/correlation/association. These are used when there has been no previous research.
• A researcher causes the independent variable to vary and records the effect on the dependent variable
• Extraneous variables are 'nuisance' variables that 'muddy the water' and may make it difficult to detect an effect. A researcher may control some of these.
• Confounding variables change systematically with the IV so we cannot be sure if any observed change in the DV is due to the CV or IV
• Demand characteristics refer to cues from the researcher or research situation that may reveal the aim of the study, and change participant's behaviour.
• Investigator effects are any effect the investigator's behaviour on the outcome of the research and also design decisions.
• Randomisation is the use of chance when designing investigations to control for the effects of bias
• Standardisation is using the exact same formalised procedure for all participants in a research study, otherwise differences become EVs
• Pilot studies are small scale trial runs of an investigation to test procedures so that research design can be modified
• Control groups or control conditions are used to set comparison. They act as a baseline and help establish causation.
• Single blind is where a participant doesn't know the aims of the experiment so that demand characteristics are reduced
• Double blind is where both participants and the researcher don't know the aims of the experiment to reduce demand characteristics and investigator effects.