Experimentation/ operational definitions- introduction to making a claim

Independent Variable (IV)

The variable that is manipulated or changed by the experimenter to observe its effect on the dependent variable.

Dependent Variable (DV)

The variable that is measured in an experiment, showing the outcome or effect of changes made to the independent variable.

Confounding Variables

Uncontrolled variables that might affect the dependent variable, causing confusion about whether the independent variable is actually responsible for changes in the dependent variable.

Random Assignment

A method used to place participants into experimental or control groups by chance, ensuring that each participant has an equal likelihood of being in any group. This helps control for confounding variables.

Population

The entire group of individuals or instances that researchers are interested in studying.

Sample

A subset of the population that is selected for participation in the study, representing the larger population.

Random Sampling

A method of selecting participants where each individual in the population has an equal chance of being chosen to participate in the study. This helps ensure a representative sample.

Convenience Samples

A sample that is selected based on ease of access and availability rather than random selection, which may introduce bias.

Sampling Bias

A bias that occurs when the sample selected does not accurately represent the population, often leading to skewed or inaccurate results.

Generalizability

The extent to which the results of a study can be applied or extended to the broader population beyond the sample studied.

Experimental Group

The group in an experiment that receives the independent variable or treatment being tested.

Control Group

The group in an experiment that does not receive the treatment or is exposed to a baseline condition, used for comparison with the experimental group.

Placebo Group

A subset of the control group that is given a placebo (an inactive substance or treatment) to control for the placebo effect.

Placebo Effect

The phenomenon in which participants experience changes in behavior or symptoms due to their expectations of treatment, rather than the actual treatment itself.

Single-Blind Procedure

An experimental procedure in which the participants do not know whether they are in the experimental or control group, reducing the impact of participant expectations.

Double-Blind Procedure

An experimental procedure in which both the participants and the experimenters do not know which group the participants are in (experimental or control), reducing both experimenter and participant biases.

Experimenter Bias

A form of bias that occurs when the researcher’s expectations or beliefs unconsciously influence the outcome of the study, potentially affecting the results.