ap psych unit 2

hindsight bias

the tendency to believe that you knew something after you have already learned the outcome

critical thinking

thinking that does not blindly accept arguments and conclusions; examines assumptions, assesses the source, discerns hidden values, evaluates evidence, and assesses conclusions

theory

an explanation using an integrated set of principles that organizes observations and predicts behaviors or events

hypothesis

a testable prediction

operational definition

describe concepts with precise procedures or measurements

replication

repeating the essence of a research study (usually with different participants in different situations) to see whether the findings are reproducible

case study

one individual or group is studied in depth in hopes of finding universal truths

naturalistic observation

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

survey

technique for discovering self-reported attitudes or behaviors of a group by questioning a random sample of that group; looks at many cases in less depth

sampling bias

flawed sampling process that produces an unrepresentative sample

population

all those in a group being studied, from which samples may be draw

random sample

sample that fairly represents a population because each member has an equal chance of inclusion

correlation

a measure of the extent to which two variables change together

correlation coefficient

statistical index of the relationship between two variables (from -1.0 to +1.0)

scatterplot

a graphed cluster of dots, each of which represents the values of two variables; the slope of the points suggests the direction of the relationship between the variables

illusory correlation

the perception of a relationship where none exists

experiment

research method in which an investigator manipulates one or more factors (independent variable) to observe its effect on a behavior or mental process (dependent variable)

experimental group

the group exposed to the treatment (one version of the independent variable)

control group

the group not exposed to the treatment; 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

double-blind procedure

an experiment in which both the participants and the staff are ignorant about whether the research participants have received the treatment or a placebo

placebo effect

experimental results caused by expectation; a phenomenon where the subject experiences a difference in their physical/psychological state even though they are given an inactive substance or condition

independent variable

experimental factor that is manipulated; the variable whose effect is being studied

confounding variable

factor other than the independent variable that may produce an effect in an experiment

dependent variable

the variable that may change in response to manipulations of the independent variable

validity

the extent to which a test or experiment measures or predicts what it is supposed to

descriptive statistics

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

mode

the most frequently occurring value in a distribution

mean

the average of a distribution (add all of the values and divide by the number of values)

median

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

skewed distribution

a representation of scores that lack symmetry around their average value; pulled to the right or left by extreme values

range

difference between the highest and lowest values in a distribution

standard deviation

measure of how much scores vary around the mean score

normal curve

symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (68% fall within one standard deviation)

inferential statistics

numerical data that allow one to generalize; to infer from sample data the probability of something being true of a population

statistical significance

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

culture

the enduring behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next