hindsight bias

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

amazing Randi

the magician who exemplifies skepticism. He has tested and debunked a variety of psychic phenomena

critical thinking

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, 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, often implied by a theory

operational definition

a statement of the procedures used to define research variables

replicate

repeating the essence of the research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

case study

an observation technique in which one person is studied in depth in the hope of revealing universal principles

survey

a technique for ascertaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them

false consensus effect

the tendency to overestimate the extent to which others share our beliefs and behaviors

population

all the cases in a group, from which samples may be drawn for a study

random sample

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

overconfidence

the tendency to overestimate the accurary of our knowledge

conformation bias

a tendency to search for information that confirms ones preconceptions

naturalistic observation

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

confounding variables

occurs when two variables are linked together in a way that makes it difficult to sort out their specific effects (when anyhting differs between the control and experimental group besides the independent variable)

Hawthorne effect

the tendency for people to behave differently when they know they are being studied

correlation (+/-)

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

correlation coefficient

mathematical expression of the relationship ranging from -1 to +1

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 two variables. The amount of scatter suggests the strength of the correlation

illusory correlation

the perception of a relationship where none exists

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.

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 expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which is assumed to be an active agent.

experimental condition (group)

the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable

control condition (group)

the condition of an experiment that contrasts with the experimental condition 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

independent variable

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

dependent variable

the outcome factor; the variable that may change in response to manipulations of the independent variable

measures of central tendency

a single score that represents a whole set of scores

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

mode

the most frequently occurring score(s) in a distribution

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

z-score

a measure of how many standard deviations you are away from the mean

statistically significant (p-value)

researchers report their findings as _______ if their _______ is 5% or less

frequency distributions

68% - 95% - 99.7%

culture

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

applied research

scientific study that aims to solve practical problems

basic research

pure science that aims to increase the scientific knowledge base

validity

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

reliability

the extent to which a test yields consistent results

sampling

the process of selecting participants who are members of the population that the researcher wishes to study

sample

a representative segment of a target population

representative sample

a sample that accurately reflects the characteristics of the population as a whole

stratified sampling

a variation of random sampling; census data are used to divide the country into four sampling regions. Sets of counties and standard metropolitan statistical areas are then randomly selected in proportion to the total national population

laboratory experiment

scientific method of isolating and observing variables in a controlled environment

field experiment

experimental research that takes place in a natural setting

participant variables

characteristics such as age, gender, and intelligence that vary from individual to another

situation-relevant variables

the situations for different groups in an experiment must be similar or the same, otherwise it will skew the results

group-matching

researchers attempt to categorize the subjects (by age, health status, gender, ect.) and ensure that the control group has members similar to those in the experimental group

experimenter bias

expectations by the experimenter that might influence the results of an experiment or its interpretation

single-blind procedure

research design in which participants don't know whether they are in the experimental or control group

response or participant bias

participants act the way they think the experiment wants you to act

social desirability

a source of bias in responding to questions on personality inventories that occurs when people try to make themselves "look good" even if it means giving untrue answers

response rate

out of all the surveys a researcher has distributed, the proportion that were completed and returned

descriptive statistics

statistical procedures used to describe characteristics and responses of groups of subjects

outliers

extreme values that don't appear to belong with the rest of the data

positive vs. negative skew

Positive skew = high outliers pulling mean right

Negative skew = low outliers pulling mean left

Negative skew = low outliers pulling mean left

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

line of best fit

a smooth line that reflects the general pattern in a graph

inferential statistics

numerical methods used to determine whether research data support a hypothesis or whether results were due to chance

sampling error

an error that occurs when a sample somehow does not represent the target population

Institutional Review Board (IRB)

a committee at each institution where research is conducted to review every experiment for ethics and methodology

coercion

use of force to get someone to obey

informed consent

an ethical principle requiring that research participants be told enough to enable them to choose whether they wish to participate

anonymity

the condition of being unknown

confidentiality

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

debriefing

giving participants in a research study a complete explanation of the study after the study is completed