SIR ROWEE FINALS Flashcards
is a study that obtains data from every member of a population. In
most studies, is not practical, because of the cost and/or time required.
Census:
is a study that obtains data from a subset of a
population, in order to estimate population attributes.
Sample survey:
is a controlled study in which the researcher attempts to
understand cause-and-effect relationships.
Experiment:
the researcher compares group scores on some dependent variable.
analysis phase,
attempt to understand
cause-and-effect relationships.
Observational study:
When the population is large, a sample survey has a big resource advantage
over a census.
Resources.
refers to the appropriateness of applying findings
from a study to a larger population.
Generalizability.
requires random selection.
Generalizability
Cause-and-effect relationships can be teased out when subjects are
randomly assigned to groups.
Causal inference.
refers to the way that observations are selected from a population to be in
the sample for a sample survey.
Sampling method
is the true value of apopulation attribute
Population parameter.
is an estimate, based on sample data, of a population
parameter.
Sample statistic.
we do not know the
probability that each population element will be chosen, and/or we cannot be sure that
each population element has a non-zero chance of being chosen.
non-probability sampling methods,
Non-probability sampling methods offer two potential advantages -
convenience and cost.
is made up of people who self-select into the
survey.
Voluntary sample.
is made up of people who are easy to
reach.
Convenience sample.
the population is divided into groups, based on some characteristic.
Then, within each group, a probability sample (often a simple random sample) is selected.
a. Stratified sampling Method
every member of the population is assigned to one, and only one, group.
Each group is called a cluster.
cluster sampling,
we select a sample by using combinations of different sampling
methods.
Multistage Sampling
we create a list of every member of the population.
systematic random sampling,
a researcher manipulates one or more variables, while holding all other
variables constant.
experiment,
(also called a factor) is an explanatory
variable manipulated by the experimenter.
Independent variable.
refers to steps taken to reduce the effects of extraneous variables
CONTROL
refers to the practice of using chance methods
Randomization.
