
hindsight bias
the tendency to believe after learning an outcome that one would have forseen it

critical thinking
 thinking that does not blindly accept arguments and conclusions
 it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions

theory
an explanation using 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 procedures used to define research variables
 Ex. human intelligenceehat an intelligence test measures

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

case study
an observation technique in which one person is started in depth in the hope of revealing universal priniciples

survey
a technique for ascertaining the selfreported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group

population
all cases in a group being studied, from which smaples may be drawn

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

naturalistic observation
observing and recording behavior in naturally occuring situations without trying to manipulate and control the situation

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

scatterplots
 a graphed cluster of dots, each of which represents the values of two variables
 slope of the points suggests the direction of the relationship between two variables
 amount of scatter suggests the strength of the correlation (little scatter indicates high correlation)

illusory correlation
the perseption of a relationship where none exists

experiment
 a research method in which a researcher directly manipulates one or more factors to observe the effect on some behavior or mental process
 make it possible to establish causeeffect relationship

random assignment
the procedure of assigning participants to the experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups

doubleblind procedure
 an experimental procedure in which neither the experimenter nor the research participants are aware of which group is recieving the treatment
 used to prevent experimenters' and participants expectations from influenceing the results of an experiment

placebo effect
occurs when the results of an experiment are cuased by expectations alone

experimental group
participants in an experiment are exposed to the independent variable being studied

control group
group in which the treatment of interest or independent variable is withheld so that comparison to the experimental condition can be made

independent variable
the factor being manipulated and tested by the investigator

dependent variable
 the factor being measured by the investigator
 the factor that may change in response to manipulations of the independent variable

mode
 the most frequently occuring score in a distribution
 simplest measure of central tendency to determine

mean
the arithmetic average, the measure of central tendency computed by adding the scores in a distribution and dividing by the number of scores

median
the score that falls at the 50th % cutting a distirbution in half

range
a meausure of variation computed as the difference between the highest and lowest scores in a distribution

standard deviation
 a computed measure of how much scores in a distribution deviate around the mean
 more precise measure of variation than the range because it is based on every score in the distribution

normal curve
the symetrical, bellshaped distribution describing many types of psychological data, in which most scores fall near the mean, with fewer and fewer at the extremes

statistical significance
an obtained result, such as the difference between the average for two smaples, very likely reflects a real difference rather than sampling variation or chance factors

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

