Chapter 4 Flashcards
(24 cards)
Define: aggregate
a quantity that is created by combining the values of many individual cases
Define: control group
in an experiment, the subset of cases that is not exposed to the main causal stimulus under investigation
Define: correlational studies
synonymus with “observatioanl studies”
Define: cross-sectional observational studies
a research design that focuses on variation across spatial units at a single time unit
Define: data set
synonym for “data”. A collection of variable values for at least two observations.
Define: datum
the sigualar form of the word data
Define: experiments
research designs in which the reseracher both controsl and randomly assigns values of the independent variable to the paricipants
Define: external validity
the degree to which we can be confident that the results of our analysis apply not only to the participants and circumstances in the study, but also to the population more broadly constructed.
Define: field experiment
an experimetnal study that occurs in the natural setting where the subjects normally lead their lives
Define: internal validity
the degree to which a study produces high levels of confidence about whether the indepndent variable causes dependent variable
Define: natural experiment
situations in nature that are not properly defined as experimetns but the values of the independent variable arise naturally in such a way as to make it seem as if true random assignment by a researcher has occurred
Define: observational studies
research designs in which the researcher does not have control over values of the independent variable, which occur naturally; it is necessary that there be some degree of variability in the independent variable across cases, as well as variation in the dependent variablle.
Define: placebo
in an experiment, an innocuous stimulus iven to the control group
Define: population
the entire set of cases to which our theory applies
Define: random assignment
when the participants for an experiment are assigned randomly to one of several possible values of X, the independent variable.
Define: random sampling
a method of selecting individual cases for a study in which every member of the underlying population has an equal probability of being selected.
Define: replication
a scientific process in which reserachers implement the same procedures repeatedly in identical form to see if the relationships hold in a consistent fashion
Define: research designs
the strategies that a researcher employs to make comparisons with the goal of evaluating causal claims
Define: sample of convenience
a sample of cases from the underlying population in which the mechanism for selecting cases is not random
Define: spatial units
the physical unit that forms the basis for observation
Define: survery experiment
a survery research technique in which the interviewing process includes experimental randomization in the survey stimulus
Define: time units
the time-based unit that forms the basis for observation
Define: time-series observational studies
a reasearch design that focuses on variation within a single spatial unit over multiple time units
Define: treatment group
in an experiment, the subset of cases that is xposed to the main causal stimulus under investigation
