UNIT 0 VOCAB

Hindsight Bias

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

Overconfidence

The tendency to overestimate our knowledge or abilities, driving us to quick thinking rather than correct thinking. 

Perceiving order in random events

Seeing patterns or meaning in random data when none exist.

Peer reviewers

Scientific experts. Who evaluates 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.

Falsifiable

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.

Replication

Repeating the essence of a research study, usually with different participants in 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 hopes of revealing universal principles.

Naturalistic observation

A non-experimental technique of observing and recording. behavior in naturally occurring situations without trying to manipulate and 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 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 of 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 (from -1.00 to +1.00).

Variable

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

Scatterplot

A method to represent the values of two variables through a graphed clustered dot. With little scatter meaning high correlation, and high scatter meaning little correlation.

Illusory correlation

Creating a correlation between variables when none exists, or perceiving a stronger correlation than what exists. 

Regression toward the mean

A statistical phenomenon, where extreme results or events tend to regress towards the average.

Experiment

A research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors.

Experimental group

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

Control group

In an experiment, the group 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 groups by chance, thus minimizing preexisting differences between the different groups.

Single-blind procedure

An experimental procedure in which the research participants are ignorant (blind) about whether they have received the treatment or a placebo.

Double-blind procedure

An experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies. 

Independent variable

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

Confounding variable

In an experiment, a factor other than the factor being studied that might influence a study’s results.

Experimenter bias

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

Dependent variable

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

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 that relies on in-depth narrative data that are not translated into numbers. 

Informed consent

Giving potential participants enough information about the study for them to choose whether they want to participate or not. 

Debriefing

To fully debrief participants about an experiment afterwards, giving information about the purpose of the experiment and any deception that may have occurred. 

Descriptive statistics

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

Histogram

A bar graph depicting frequency distribution

Mode

The most frequently occurring scores(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 lacks 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 scores

normal curve

A symmetrical bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean, 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.

Statistically significant

A statistical statement of how likely it is that a result occurred by chance, assuming there is no difference between the population being studied. 

Effect size

The strength of the relationship between two variables. The larger the effect size, the more one variable can be explained by the other.

Critical thinking

Thinking that does not blindly accept arguments and conclusions.  Instead, it examines assumptions, appraises the source, discerns hidden biases, evaluates evidence, and assesses conclusions.

Three key elements of the scientific attitude

Curiosity, skepticism, and humility.