AP Psychology Unit 0 Vocab

Critical thinking - The Scientific attitude - curiosity + skepticism + humility prepares us to think harder and smarter.

Hindsight bias - (also known as the l-knew-it-all-along phenomenon) is the tendency to believe, after learning an outcome, that we would have foreseen it.

Peer reviewers - other scientists who are experts - evaluate a study'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. For example, human intelligence may be operationally defined as what an intelligence test measures. (also known as operationalization)

Replication- repeating the essence of the research study, usually with different participants in different situations, to see whether the basic finding can be reproduced. (precise operational definitions are vital for the replication of an experiment)

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 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 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 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 graphical cluster of dots, each of which represents the value of the two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter suggests a high correlation).

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 (regress) toward 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 processes (The dependent variable). By random assignment of participants, the experimenter aims to control the other relevant factors.

Experimental group - in an experiment, the group exposed to the treatment- that is, to 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 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 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.

Placebo effect - experimental results caused by the 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 - is an experiment, the factor that 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.

Experimental bias - Bias caused when researchers 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 is supposed to happen.

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 post-experimental explanation of a study, including its purpose and any deceptions, to its participants.

Descriptive statistics - numerical data used to measure and describe characteristics of groups; including measures of central tendency and measures of variation.

Histogram - a bar graph depicting a 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 lack symmetry around their average value.

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

Standard deviation - a computed measure of much scores vary around the mean score.

Normal curve - A symmetrical, bell-shaped curve describes the distribution of many types of data; most scores fall near the mean (about 68 percent fall within one standard deviation of it) and fewer and fewer scores lie near the extremes. (also called normal distribution)

Inferential statistics - numerical data that allow one to generalize and 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 a result (such as a difference between samples) occurred by chance, assuming there is no difference between the populations 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.