Unit 0 - Research Methods and Data Interpretation

Critical Thinking —

Thinking that does not automatically accept arguments and conclusions. Rather, it examines assumptions, appraises the source, discerns hidden biases, and assesses conclusions.

Hindsight Bias —

The tendency to believe, after learning an outcome, that one would have foreseen it.

Overconfidence —

The tendency to be more confident than correct—to overestimate the accuracy of our beliefs and judgments.

Peer Reviewers —

Scientific experts who evaluate a research article's theory, originality, and accuracy.

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.

Falsifiability —

The possibility that an idea, hypothesis, or theory can be disproven by observation or experiment.

Operational Definition —

A carefully worded statement of the exact procedures (operations) used in a research study. Also known as operationalization.

Replication —

Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding can be reproduced.

Case Study —

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

Naturalistic Observation —

A non-experimental technique of observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.

Survey —

A non-experimental technique for obtaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.

Social Desirability Bias —

Bias from people's responding in ways they presume a researcher expects or wishes.

Self-Report Bias —

Bias when people report their behavior inaccurately.

Sampling Bias —

A flawed sampling process that produces an unrepresentative sample.

Random Sample —

A sample that fairly represents a population because each member has an equal chance at inclusion.

Population —

All those in a group being studied, from which random samples may be drawn.

Correlation —

A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.

Correlation Coefficient —

A statistical index of the relationship between two variables, ranging from -1.00 to 1.00.

Variable —

Anything that can vary and is feasible and ethical to measure.

Illusory Correlation —

Perceiving a relationship where none exists, or perceiving a stronger-than-actual relationship.

Regression Toward the Mean —

The tendency for extreme or unusual scores or events to fall back toward the average.

Experiment —

A research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process.

Experimental Group —

In an experiment, the group that is exposed to the treatment—the version of the independent variable being studied.

Control Group —

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Random Assignment —

Assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups.

Single-Blind Procedure —

An experimental procedure in which the research participants are unaware of whether they have received the treatment or placebo.

Double-Blind Procedure —

An experimental procedure in which both the research participants and the research staff are unaware of whether the research participants have received the treatment or a placebo.

Placebo Effect —

Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.

Independent Variable —

In an experiment, the factor that is manipulated; the variable whose effect is being studied.

Dependent Variable —

In an experiment, the outcome that is measured; the variable that may change when the independent variable is manipulated.

Confounding Variable —

In an experiment, a factor other than the factor being studied that influences a study's results.

Experimenter Bias —

Bias caused when researchers may unintentionally influence results to confirm their own beliefs.

Validity —

The extent to which a test or experiment measures or predicts what it is supposed to do.

Quantitative Research —

A research method that relies on quantifiable, numerical data.

Qualitative Research —

A research method that relies on in-depth, narrative data that are not translated into numbers.

Informed Consent —

Giving potential participants enough information about a study to enable them to choose whether they wish to participate.

Debriefing —

The postexperimental explanation of a study, including its purpose and any deceptions, to its participants.

Descriptive Statistics —

Numerical data used to measure and describe the characteristics of groups; includes measures of central tendency and measures of variation.

Histogram —

A bar graph depicting a frequency distribution.

Mode —

The most frequently occurring score(s) in a distribution.

Mean —

The arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores.

Median —

The middle score in a distribution; half the scores are above it and half are below it.

Percentile Rank —

The percentage of scores that are lower than a given score.

Skewed Distribution —

A representation of scores that lack symmetry around their average value.

Range —

The difference between the highest and lowest scores in a distribution.

Standard Deviation —

A computed measure of how much scores vary around the mean score.

Normal Curve —

The symmetrical, bell-shaped curve that describes the distribution of many physical and psychological attributes. Most scores fall near the average, and fewer and fewer scores lie near the extremes.

Inferential Statistics —

Numerical data that allow one to generalize—to infer from sample data the probability of something being true of a population.

Meta-Analysis —

A statistical procedure for analyzing the results of multiple studies to reach an overall conclusion.

Statistical Significance —

A statistical statement of how likely it is that an obtained result occurred by chance.

Effect Size —

The strength of the relationship between two or more variables. The larger it is, the more one variable can be explained by the other.

Cultural Norms —

Behavior patterns that are typical of specific groups.

Confirmation Bias —

A tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence.

Institutional Review —

The process of examining studies for ethical concerns by a committee of peers.

Informed Assent —

A participant's agreement to participate in the absence of full understanding. Commonly applies to individuals who are underage or otherwise incapable of consent.

Confidentiality —

The act of holding information in confidence, not to be released to unauthorized individuals.

Deception —

An act that misleads participants about the true purpose of a study or the events that will actually transpire.

Research Confidentiality —

The requirement for participants' data to be secured/coded for anonymity.

Variation —

A change or slight difference in condition, amount, or level.

Skewness —

A measure of the degree to which a distribution is asymmetrical.

Scatterplot —

A graphed cluster of dots, each of which represents the values of two variables. Typically used in representations of correlation.

Bimodal Distribution —

A frequency distribution that features two different values that are heavily populated with cases.