
Nomothetic explanations
A type of scientific explanation that seeks to produce a generalized understanding (ex. common causes) of classes of events

Idiographic explanations
type of scientific explanation that describes a unique set of conditions that account for the actions of a single person or set of actors at a particular time and place

Deductive reasoning
 process of reasoning in which the conclusion necessarily follows if the evidence is true
 bottom up
 making observations and then making theories

inductive reasoning
 reasoning process in which the conclusion goes beyond the evidence
 topdown
 start with a theory and look for evidence to support

objectivity
in science, the methodological condition that makes it possible for two or more people to agree on the results of an observation

intersubjective testability
a condition where two or more scientists can agree on the results of observations

ecological fallacy
incorrect use of information pertaining to an aggregate (ex. organizations) to draw inferences about the units of analysis that comprise the aggregate (ex. individual members of the organization)

correlation coefficient
 a measure of association (Pearson's r) that describes the direction and strength of a linear relationship between two variables measured at the interval or ratio level
 the square of r represents the proportion of variance in one variable that can be predicted from the other using linear regression

statistical significance
determined using tests of statistical significance to assess the likelihood that the results of an experiment or other study could have occurred by chance

exploratory research
studies undertaken to explore a phenomenon or topic about which little is known

descriptive research
studies undertaken to collect facts about a specified population or sample, e. a public opinion poll

explanatory research
studies that investigate relationships between two or more variables, attempting to explain them in causeandeffect terms

systematic measurement error
error from factors that systematically influence (bias) either the process of measurement or the concept of being measured. Systematic errors are consistent across measurements taken at different times or are systematically related to characteristics of the cases being measured (ie. the cultural bias of IQ tests) and thereby affect validity

reactive measurement effect
an effect whereby the process of measurement itself, resulting from people's awareness of being studied, produces changes in what is being measured

social desirability effect
a tendency of some respondents to bias their answers in the direction of socially desirable traits or attitudes, thereby endeavouring to enhance their selfesteem or make a favorable impression on the interviewer or researcher

sampling frame
 an operational definition of the population that provides the basis for drawing a sample
 constructed by either 1) listing all cases from which a sample may be selected or 2) defining population membership by a rule that provides a basis for case selection

probability sample
sampling based on a process of random selection that gives each case in the population an equal or known chance of being included in the sample

nonprobability sample
processes of case selection other than random selection

confidence interval
a range (interval) within which a population value is estimated to lie at a specific level of confidence; used to qualify sample estimates to take into account sampling error. Ex. a researcher might say that she is 99% confident (confidence level) that the mean personal income for a population lies within plus or minus $359 of the sample mean of $18, 325 (confidence interval is $18, 684  $17, 966)

sample bias
systematic error or bias in sample results caused by problems in executing the sampling plan, such as incomplete sampling frames and incomplete data collection (notathome respondents, refusals, etc)

nonresponse bias
in survey sampling, when nonrespondents (sampled individuals who don't respond or can't be contacted) differ in important ways from respondents

