Mini Stats and Stuff

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

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

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

a testable prediction, often implied by a theory

• a statement of the procedures (operations) used to define research variables
• for example, human intelligence may be operationally defined as what an intelligence test measures

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

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

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

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

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

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

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

a statistical index of the relationship between two things (from -1 to +1)

• 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 (little scatter indicates high correlation)

the perception of a relationship where none exists

a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process

assigning participants to experimental and control groups by chance, thus minimizing pre-existing differences between those assigned to the different groups

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

• experimental results caused by expectations alone
• Any effect on behavior caused by the administration of an inert substance or condition, which recipient assumes is an active ingredient

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

• the group that is not exposed to the treatment
• Contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment

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

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

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

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

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