Unit II Vocab

hindsight bias

finding that something has happened makes it seem inevitable (I-knew-it-all-along phenomenon)

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 behavior or events.

hypothesis

a testable prediction, often implied by a theory.

operational definition

a statement of the procedures (operations ) used to define research variables.

replication

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

case study

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

survey

a techniques for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.

population

all the cases in a group being studied, from which samples may be drawn.

random sample

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

naturalistic observation

observing and recording behavior in naturally occurring 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.

scatterplot

a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggest 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 on which an investigator manipulates one or factors (independent variable) 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.

random assignment

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between thus assigned to the different groups.

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 insert substance or condition, which the recipient assumes is an active agent.

experimental group

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

control group

in an experiment, the group that is not exposed to the treatment; contrast with the experimental group and serves as a comparison for evaluating the effects of the treatment.

independent variable

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

confounding variable

a factor other then the independent variable that might produce an effect in an experiment.

dependent variable

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

mode

the most frequently occurring score(s) in a distribution.

mean

the arthritic average of a distribution, obtained by adding the scores and then dividing the number of scores.

median

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

range

the difference between the highest and lowest cores in a distribution.

standard deviation

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

normal curve

a symmetrical ball-shaped curve that describes the distribution of many types of data, most scores fall near the mean and fewer and fewer near the extremes.

statistical significance

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

culture

the enduring behaviors, ideas, attitudes, and traditions shard by a group of people and transmitted from generation top the next.

informed consent

an ethical principle the research participants be told enough 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.