Variables

• An independent variable is the one that is manipulated or changed by the researcher.
• A dependent variable is the one which is measured.
• The independent variable is known as the IV.
• The dependent variable is known as the DV.
• In an experiment, the independent variable (IV) is the variable that the researcher manipulates and is assumed to have a direct effect on the dependent variable (DV).
• IVs and DVs only occur in experiments, as cause and effect is predicted between the two.
• IVs and DVs do not feature in correlation studies, as correlations look for a relationship between co-variables, so cause and effect cannot be established.
• The dependent variable in an experiment is the variable that is being measured or observed and is expected to change in response to the independent variable.
• The independent variable is manipulated by the researcher, while the dependent variable is the outcome or response that is measured or observed.
• Extraneous variables (EV) are those variables, other than the IV, that might affect the results (the DV).
• Extraneous variables are unwanted factors in a study that, if not accounted for, could negatively affect the data.
• Extraneous variables are variables that are not the focus of the study but can still influence the results, potentially leading to confounding or inaccurate conclusions.
• Extraneous variables are usually environmental factors that a researcher must aim to control, to ensure a fair test for all participants.
• Extraneous variables are anything extra that might influence the outcome of the study.
• Participant variables are differences between participants which might affect the outcome of the results (e.g. age, gender or IQ).
• Researcher variables are factors such as the researcher’s behaviour, appearance or gender which could affect the participants. These should be controlled and made consistent throughout the experiment.
• Situational variables are those in the setting where the experiment takes place, such as lighting, noise and temperature etc, which might affect the results.
• Participant variables are characteristics or traits of the individuals participating in a study. They can affect the results of a study by influencing how participants respond to the study materials or tasks, potentially introducing bias or confounding variables.
• Researcher variables are characteristics or actions of the researcher that can potentially influence the outcome of an experiment. They should be controlled to ensure that any observed effects are truly due to the IV and not the actions or biases of the researcher.
• Situational variables in an experiment refer to factors or conditions that can potentially influence the outcome of the study, such as the physical environment, time of day, or presence of other people.
• Confounding variables bring about a change in the DV which is wrongly attributed to the IV. They can affect the internal validity of the research.
• Confounding variables may not be apparent until after the study has taken place.
• Confounding variables may unwillingly affect the results of a study. For example, an individual with a photographic memory will perform better in memory tasks.
• Confounding variables can introduce bias and make it difficult to determine the true relationship between the IV and DV in a research study, so compromising the internal validity.
• Extraneous variables that are not controlled for and actually do affect the DV are called confounding variables.