Psychology Research Methods and Cognitive Biases Overview

Cognitive Biases

Systematic patterns of deviation from norm or rationality in judgment

confirmation bias

Tendency to search for, interpret, and remember information that confirms one's preconceptions

Hindsight bias

The "I-knew-it-all-along" effect; tendency to see events as having been predictable after they have already occurred

Overconfidence

Excessive confidence in one's own answers or abilities

Qualitative research

Research that involves non-numerical data to understand concepts, opinions, or experiences

Quantitative

Research that involves numerical data to quantify variables and analyze statistical relationships

Research Design

The overall strategy that you choose to integrate the different components of the study in a coherent and logical way

Independent Variable

The variable that is manipulated to observe its effect on the dependent variable

Random Assignment

Assigning participants to experimental and control groups by chance, minimizing preexisting differences

Case Study

An in-depth analysis of an individual, group, or event

Correlation

A measure of the relationship between two variables

Meta-Analysis

A statistical technique for combining the findings from independent studies

Naturalistic observation

Observing subjects in their natural environment without interference

Quasi-Experiment

A quasi-experiment is a research method that attempts to establish a cause-and-effect relationship between variables, but without using random assignment. Instead, participants are assigned to groups based on non-random criteria, such as self-selection or administrator selection

Hypothesis

A testable prediction about the relationship between two or more variables

Falsifiable

A hypothesis that can be disproven by experimental results

Operational Definition

A clear, precise, typically quantifiable definition of your variables

Replication

Repeating a study to see if the original findings can be reproduced

Dependent Variable

The variable that is measured to see how it is affected by the independent variable

Confounding Variable

An outside influence that changes the effect of a dependent and independent variable

Variables

Elements, features, or factors that are liable to vary or change

Mean

The average of a set of numbers

Median

The middle value in a set of numbers

Mode

The most frequently occurring value in a set of numbers

Range

The difference between the highest and lowest values in a set

Standard Deviation

A measure of the amount of variation or dispersion in a set of values

Normal Curve

A bell-shaped curve that shows the distribution of data

Percentile Rank

The percentage of scores in its frequency distribution that are equal to or lower than it

Positive Skew

When a distribution has a long tail on the right side

Negative Skew

When a distribution has a long tail on the left side

Bimodal Distribution

A distribution with two different modes

Regression toward the Mean

The phenomenon that if a variable is extreme on its first measurement, it will tend to be closer to the average on its second measurement

Claim/Norm

A statement or assertion that is open to challenge and that requires justification

Participants

Individuals who take part in a research study

Sample

A subset of the population that is used to represent the entire group

Population

The entire group that you want to draw conclusions about

Representative Sample

A sample that accurately reflects the characteristics of the population as a whole

Random Sampling

A method of selecting a sample from a population in such a way that every possible sample has a predetermined probability of being selected

Convenience Sampling

Choosing individuals who are easiest to reach

Sampling Bias

A bias in which a sample is collected in such a way that some members of the intended population are less likely to be included

Generalizability

The extent to which findings from a study can be applied to a larger population

Experimental Group

The group in an experiment that receives the variable being tested

Control Group

The group in an experiment that does not receive the experimental treatment

Placebo

A substance with no therapeutic effect, used as a control in testing new drugs

Placebo Effect

Improvement resulting from the mere expectation of improvement

Single-blind Procedure

An experimental procedure in which the participants are unaware of the treatment they are receiving

Double-blind Procedure

An experimental procedure in which both the participants and the researchers are unaware of who is receiving the treatment

Experimental Bias

A bias that occurs when a researcher's expectations or preferences about the outcome of a study influence the results obtained