AP Psych Unit 1 Scientific Foundations of Psychology

Hindsight Bias

A cognitive bias that occurs when individuals perceive past events as having been more predictable than they actually were, often leading to overconfidence in their foresight.

Theory

A systematic explanation of an observation or phenomenon, often supported by evidence and used to predict future outcomes in psychology.

Hypothesis

A testable prediction derived from a theory, used to drive research and experimentation in psychology.

Operational definition

A clear and precise statement that defines how variables are measured or manipulated in a research study, ensuring that concepts can be tested and replicated.

Replication

The process of repeating a study to determine if the original findings can be consistently reproduced

Case study

A research method involving an in-depth analysis of a single individual, group, or event to explore complex psychological phenomena.

Naturalistic observation

A research method that involves observing subjects in their natural environment without manipulation or interference, allowing for the collection of data in a real-world context.

Survey

A research method that involves administering questionnaires or interviews to gather data from a large group of respondents about their thoughts, feelings, or behaviors.

Sampling bias

The error that occurs when the sample selected for a study is not representative of the larger population, leading to skewed results.

Population

The complete set of individuals, items, or data that researchers are interested in studying, from which a sample may be drawn for analysis.

Random sample

A subset of a population chosen randomly, ensuring that every individual has an equal chance of being selected, which helps minimize bias in research.

Correlation

A statistical measure that describes the extent to which two variables change together, indicating the direction and strength of their relationship.

Correlation coefficient

A numerical value that quantifies the strength and direction of the relationship between two variables, ranging from -1 to +1.

Variable

Any factor or element that can change or be changed in an experiment, affecting the outcome of the research.

Scatterplot

A graphical representation of the relationship between two quantitative variables, where each point represents an observation. It helps visualize patterns, trends, and correlations.

Illusory correlation

The perception of a relationship between two variables when none actually exists, often influenced by cognitive biases.

Regression toward the mean

The phenomenon where extreme observations tend to be closer to the average upon subsequent measurement, indicating a return to typical levels.

Experiment

A research method that involves manipulating one or more independent variables to determine their effect on a dependent variable, allowing researchers to establish cause-and-effect relationships.

Experimental group

The group in an experiment that receives the treatment or intervention being tested, used for comparison against the control group.

Random assignment

The process of assigning participants to different groups in an experiment using random methods, ensuring that each participant has an equal chance of being placed in any group. This helps control for biases and enhance the validity of the results.

Double-blind procedure

A research design where both the participants and the experimenters are unaware of who is receiving the treatment or intervention, minimizing bias.

Placebo

A substance with no therapeutic effect used as a control to test the efficacy of a drug or treatment.

Independent variable

the factor that a researcher manipulates or changes in an experiment to observe its effect on another variable

Confounding variable

a third, unmeasured variable that is linked to both the independent and dependent variables in a study, distorting the true relationship between them and potentially creating a false cause-and-effect connection

Dependent variable

the factor that is measured or observed, representing the outcome or effect of an experiment that is expected to change in response to an independent variable

Informed consent

an ongoing communication process where a person voluntarily agrees to participate in treatment or research after receiving and understanding all the necessary information about the nature of the services, potential risks and benefits, limits of confidentiality, and any alternatives available

Debriefing

a structured discussion that takes place after a research study or experimental procedure

Descriptive statistics

used to summarize, organize, and describe the basic features of a dataset

Histogram

a type of bar graph used to visualize the distribution of a continuous variable by grouping data into bins and showing the frequency of data points within each bin

Mode

the most frequent value in a data set (a measure of central tendency) or a characteristic manner of behavior

Median

a measure of central tendency that represents the middle value in a dataset, with half the data points falling above it and half below it

Skewed distribution

asymmetrical data that doesn't follow a normal bell curve

Range

the difference between the highest and lowest values in a data set, indicating data variability

Standard distribution

a normal distribution (a bell-shaped curve) with a mean of 0 and a standard deviation of 1, where all scores are converted to z-scores

Normal Curve

a symmetrical, bell-shaped graph that represents the distribution of traits and scores across a population, where most people score around the average (the mean) and scores decrease equally toward the extremes

Inferential statistics

techniques that allow researchers to generalize findings from a specific sample to a larger population

Statistical significance

a research outcome is unlikely to have occurred by random chance, suggesting a real effect or relationship between variables