AP Psychology Chapter 0

Operational Definition

In a study, it is a clear, specific explanation of how a variable is measured.

Target population

The entire group you want to study

Random Sample

A fair way of choosing people from the target population so everyone has an equal chance

Representative Sample

A smaller group that actually matches the larger population in important ways (age, gender, background, etc)

Random Assignment

Once you have your sample, you randomly place each participant into an experimental group or a control group

Sampling Bias

When some members of the population have a better or worse chance of being included in the study

Convenience Sample

A sample chosen based on ease of access rather than random selection

You can generalize if…

• the sample is representative of the target population

• random sampling was used

• large enough sample to reflect diversity

• procedures were clear and unbiased

naturalistic observation

Watching participants in their natural environment without interfering

Case study

In-depth examination of a rare event with an individual or small group

meta-analysis

a statistical method of combining results from many different studies on the same topic to look for overall trends

correlational study

examining the relationship between two or more variables

experiment

researchers manipulates one or more variables (independent variables) and measures the outcome (dependent variables) to test for cause and effect

informed consent

a person voluntarily agrees to participate in a study after receiving and understanding accurate information about its nature, risks, benefits, and alternatives

Safety/minimizing harm

protection, A persons health and safety is prioritized over scientific discovery

confidentiality

privacy, can’t share names or a singular persons results but can share average group results.

debrief

Results, intention to share purpose of deception

independent variable

the factor that an experimenter manipulates or changes to observe its effect on a dependent variable (DV), which is the measured outcome

dependent variable

the outcome or behavior that is measured in an experiment to see if it is affected by a change in the independent variable

confounding variable

a third, unmeasured variable that influences both the independent and dependent variables in a study, making it difficult to determine the true cause-and-effect relationship between the two variables of interest.

experimenter bias

the unconscious influence of a researcher's expectations on an experiment's design, conduct, and interpretation, leading to skewed results.

single-blind experiment

only the participants are unaware of which treatment or intervention they are receiving, while the researchers administering the study know the assigned conditions

double-blind experiment

a research design where neither the participants nor the experimenters know who is receiving the actual treatment and who is receiving a placebo or control.