Mrs. Clements
 An official, usually periodic
enumeration of an entire population,
often including the collection of
related demographic information.
 Robert Goldenkoff, 2010 Census Video
 a group drawn from a population
and used to estimate the
characteristics of the population.
 A sample is used because a census
is expensive, time –consuming
and complex.
GALLUP
 occurs when the way that the
sample is selected systematically
excludes part of the population
 Literary Digest: The Poll that
Changed Polling
VERSUS
 list of possible subjects who could
be selected in a sample
 If the sampling frame is not equal
to the population, the sample will
be biased in the same way the
sampling frame is bias.
 choosing the individuals that
are easiest to reach
 Mall Surveys
 This is also an example of
selection bias.
Occurs when the response of the sample is swayed by a
factor other than the variable at hand
 Wording of the question
 Honesty
 Order of the choices
 Demeanor of the interviewer
occurs when responses are not obtained from all
individuals selected for inclusion in the sample
 mail surveys
 telephone surveys
 self-selection
 represents members
of the population with
strong opinions
 Dancing with the Stars