50 terms

COM 3311

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the aim of science
is to produce knowledge, to understand and explain some aspect of the world around us.
concepts
abstractions communicated by words or other signs that refer to common properties among phenomena
explanations
are attempts to satisfy curiosity
empirical generalization
a generalization or hypothesis inductively derived from observations
hypothesis
an expected but unconfirmed relationship among two or more variables
theory
a logically interconnected set of propositions that show how or why a relationship occurs
serendipity pattern
unanticipated findings that cannot be interpreted meaningfully in terms of prevailing theories and that give rise to new theories
inductive reasoning
a reasoning in which the conclusion goes beyond the evidence
deductive reasoning
a process of reasoning in which the conclusion necessarily follows if the evidence is true
aggregate data
information about one set of units that is statistically combined to describe a large social unit
variables
characteristics of units that vary, talking on different values, categories, or attributes for different observations
ecological fallacy
when you judge based on one unit of analysis
extraneous variables
all variables other than the independent and dependent variables in a hypothesized relationship.
other units of analysis that spring up between A and B
antecedent variables
occurs prior in time to both the independent and dependent variable.
intervening variable
a variable that is intermediate between two other variables in a casual chain
"affects A and B"
quantitative variable
a variable that has categories that express numerical distinctions
qualitative variable
a variable that has has discrete categories, usually designated by words or labels and nonnumerical between categories
positive/direct relationship
a relationship in which an increase in the value of one variable is accompanied by an increase in the value of the other
negative/inverse relationship
a relationship in which an increase in the value of one variable is accompanied by a decrease in the value of the other
conceptualization
the process of formulating and clarifying concepts
operationalization
the detailed description of the research operations or procedures necessary to assign units of analysis to the categories of a variable in order to represent conceptual properties
4 types of measurement
nominal,ordinal,interval,ratio
nominal measurement
a system in which cases are classified into to or more categories on some variable.
creates categories,always exhaustive,mutually exclusive
ordinal measurement
numbers indicate the rank order of cases on some variable
ranking,ordering
interval measurement
has qualities of the nominal and ordinal levels plus the requirement that distances or intervals between "numbers" represent equal distances in the variable being measured
ratio measurement
includes the features of the other levels plus an absolute (non-arbitrary) zero point
reliability
is concerned with questions of stability and consistency
same results should appear
validity
the congruence or "goodness of fit" between an operational definition and the concept it is purported to measure
"accuracy"
systematic measurement errors
results from factors that systematically influence either the process of measurement or the concept being measured
(ie. IQ test)
test re-test method
test the same people several times
split half method
a scale or index is applied once to a sample of cases, after which the items of the scale are divided into halves usually by random selection: each half is then treated as a subtest with the results of two subtests correlated to obtain an estimate of reliability
inter coder reliability
when multiple people use the same measurement
face validity
refers simply to a personal judgement that an operational definition appears,on the face of it,to measure the concept it is intended to measure
"based on what we see, is the instrument valid"
content validity
concerns the extent to which a measure adequately represents all facets of a concept
"does it cover a wide scope?"
criterion-related validity
applies to measuring instruments that have been developed for some practical purpose other that testing hypotheses or advancing scientific knowledge
sample
a subset of cases selected from a population
simple random sampling
the basic probability sampling design that is incorporated in all the more elaborate probability sampling designs. (lottery)
stratified random sampling
the population is first subdivided into two or more mutually exclusive segments, called strata, based on categories of one or more combination of relevant variables
cluster sampling
a probability sampling procedure in which the population is broken down into natural groupings or area, called clusters, and a random sample of clusters is drawn
systematic sampling
a probability sampling procedure in which cases are selected from an available list at a fixed interval after after a random start
convenience sampling
based on luck, the people that are present at the moment, accidental
purposive sampling
a form of non probability sampling that involves the careful selection of typical cases that represent relevant dimensions of the population
quota sampling
a form on non probability sampling that involves the allocation of quotas of cases for various strata and the nonrandom selection of cases to fill the quotas
snowball sampling
uses a process of chain referral: when members of the target population are asked to provide names of other members of the target population
exhaustive
the measurement requirement that a measure includes all possible values or attributes of a variable so that every case can be classified
validity
the congruence or "goodness of fit" between an operational definition and the concept it is purported to measure
probability sampling
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
non-probability sampling
processes of case selection other than random selection
discriminant validity
the extent to which a measure of a particular concept differentiates that concept from other concepts from which it is intended to differ
mutually exclusive
the measurement requirement that each case can be placed in only one category of a variable