AP Psychology Unit II, Research Methods: Thinking Critically With Psychological Science

Hindsight Bias

The tendency to believe, after learning an outcome, that one what have foreseen it. (Also known as the I-knew-it-all-along phenomenon)

Critical Thinking

Thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, assesses the source, discerns hidden values, evaluated evidence, and assesses conclusions.

Theory

An explanation using an integrated set of principles that organizes observations and predicts behaviors or events.

Hypothesis

A testable prediction, often implied by a theory.

Operational Definition

A carefully worded statement of the exact procedures used in a research study.

Replication

Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances.

Case Study

A descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles.

Naturalistic Observation

Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.

Survey

A research method used for collecting data from a group of individuals to gather self-reported information about their attitudes, beliefs, or behaviors.

Sampling Bias

A flawed sampling process that produces an unrepresentative sample, leading to skewed results in research.

Population

The entire group of individuals or instances about whom researchers want to draw conclusions.

Random Sample

A subset of individuals selected from a larger population, where each member has an equal chance of being chosen, ensuring that the sample represents the population accurately.

Correlation

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

Correlation Coefficient

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

Scatterplot

A graphical representation of two variables, where each point represents an observation, used to visualize the relationship between the variables.

Illusory Correlation

The perception of a relationship between two variables when none exists, often due to cognitive biases.

Experiment

A research method that involves manipulating one variable to determine its effect on another variable, allowing for the establishment of cause-and-effect relationships.

Experimental Group

A group in an experiment that receives the treatment or intervention being tested, allowing for comparison with the control group.

Control Group

A group in an experiment that does not receive the treatment or intervention, serving as a baseline to compare against the experimental group.

Random Assignment

The process of randomly assigning participants to different groups in an experiment to ensure that each group is similar at the start, minimizing pre-existing differences.

Placebo Effect

The phenomenon where participants experience changes in their condition simply because they believe they are receiving treatment, even if they are not.

Independent Variable

The variable that is manipulated or changed in an experiment to observe its effects on the dependent variable.

Confounding Variable

A factor other than the independent variable that may influence the dependent variable, potentially skewing the results of an experiment.

Dependent Variable

The variable that is measured in an experiment to assess the effect of the independent variable.

Validity

The extent to which a test or experiment measures what it claims to measure, ensuring accurate results and interpretations.

Descriptive Statistics

Statistical methods that summarize and organize data, providing a clear overview of its characteristics.

Histogram

A graphical representation of the distribution of numerical data, using bars to show the frequency of data points within specified intervals.

Mode

The value that appears most frequently in a data set, representing the most common observation.

Mean

The average value of a data set, calculated by dividing the sum of all values by the number of values.

Median

The middle value in a data set when the numbers are arranged in order, or the average of the two middle values if the data set has an even number of observations.

Skewed Distrobution

A distribution that is not symmetrical, where one tail is longer or fatter than the other, indicating a bias in the data.

Range

The difference between the highest and lowest values in a data set, providing a measure of variability.

Standard Deviation

A measure of the amount of variation or dispersion in a set of values, indicating how much individual data points differ from the mean.

Normal Curve

A bell-shaped curve that represents the distribution of a set of data, where most values cluster around the mean and probabilities for values further away from the mean taper off symmetrically.

Inferential Statistics

Methods used to make inferences or generalizations about a population based on a sample of data. They help determine the likelihood that a result is due to chance.

Culture

The shared beliefs, values, customs, and behaviors of a group that influence their perceptions and interactions.

Informed Consent

A process by which participants are fully informed about the nature of a study, including any potential risks, and voluntarily agree to participate.

Debriefing

The process of providing participants with a full explanation of the study after it has concluded, including its purpose, any deception involved, and the results.

Statistical Significance

A statistical measure that indicates whether the results of a study are likely due to chance or represent a true effect in the population.

Double-Blind Procedure

A research method in which both the participants and the researchers are unaware of who receives the treatment or placebo, minimizing bias in the results.