ap psych vocab: unit 0

critical thinking

thinking that does not automatically accept arguments and conclusions

hindsight bias

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

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.

operational definitions

a carefully worded statement of the exact procedures (operations) used in a research study

replicate

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 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 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 things (from −1.00 to +1.00).

variables

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

scatterplots

a graphed cluster of dots, each of which represents the values of two variables

illusatory correlation

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

regression towards 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 to observe the effect on some behavior

experimental group

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

control group

the group not exposed to 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.

placebo effect

experimental results caused by expectations alone

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.

informed consent

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

debrief

a structured discussion that takes place after a research study or other experience

descriptive statistics

numerical data used to measure and describe characteristics of groups; include measures of central tendency and measures of variation.

histogram

a bar graph depicting a frequency distribution.

percentile rank

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

skewed

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

standard deviation

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

normal curve

a symmetrical, bell-shaped curve that describes the distribution of many types of data

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

effect size

the strength of the relationship between two variables