Quiz (Chapter 5)
Foundations of Inferential Statistics
Statistical Inference
 (T/F) If a researcher has absolutely no interest beyond the specific
data he/she collects, there is no need whatsoever for any statistical
techniques that are inferential in nature.
 (T/F) The purpose of inferential statistics is to make scientific
guesses as to the value of the unknown sample statistic on the basis
of the value of the known population parameter.
 Statistical inference involves _____ . (a) proving things (b) making
educated guesses
 Suppose 4 books are pulled off a library shelf containing 25 books,
with those 4 books considered to be the sample. Would the population
in this example be a "tangible" population or an "abstract" population?
The Concepts of Statistics and Parameter
 (T/F) The statistical focus in section "a" of Figure 5.1
is different from the statistical focus in section "b."
 What symbol is used to denote the population's mean? The population's
standard deviation?
 The Greek letter ___ denotes Pearson's productmoment correlation
in the population.
 (T/F) In inferential statistics, the sample statistic & the population
parameter MUST deal with the same concept (e.g., if the statistic is
the mean, then the parameter must be the mean).
 (a) N is to s as n is to __. (b) m
is to __ as r is to r.
Types of Samples
 If every object in the population has an equal chance of being selected
for inclusion in the sample, then the word ______ describes the way
in which the sample was selected.
 (T/F) The notion of a "sampling frame" comes into play only when
the population is tangible.
 For each of these samples, indicate whether it is a probability sample
or a nonprobability sample:
 convenience sample
 purposive sample
 quota sample
 simple random sample
 stratified random sample
 snowball sample
 cluster sample
 systematic sample
 If a stratified random sample of 100 people is extracted from a population
that contains 60% females and 40% males, how many males will there be
in the sample?
 If an instructor collected data from everyone enrolled in his/her
class, and if those data were then treated as if they had come from
a sample, what would be the official name for this kind of sample?
 On the surface (but only on the surface), a quota sample looks
somewhat like a __________ sample.
The Problems of Low Response Rate, Refusals to Participate, and Attrition
 What does the term "response rate" mean? Should it be high
or low?
 (T/F) If a mailed questionnaire is sent to a random
sample of individuals in a population, the problem of low response rate
cannot logical develop.
 (T/F) In studies involving a mailed questionnaire, researchers can't
do anything to bring about a high response rate and must "live with"
whatever response rate they get.
 The possible problem of a _________ can be investigated by comparing
(a) responses from a sample of folks who initially do not respond
with (b) responses from those folks who initially did respond.
 Some researchers use the word ________ to mean the same thing as
"attrition."
 In Excerpt 5.24, the attrition rate at the 3month assessment was
equal to
 19%
 54%
 73%
A Few Warnings
 The first warning advises you to be on guard when reading research
articles because there may be a mismatch between _____ and the destination
of the inferential claims.
 If a researcher has a population of 1,000 individuals, which of these
samples would be better than the other?
 A probability sample of 50 individuals
 A nonprobability sample of 300 individuals
 Suppose a researcher shuffles well a deck of playing cards and then
blindly gives a card to each member of a group of 50 individuals.
Also suppose that the researcher then collects data from those folks
who received a diamond (but not from those who received a club, a heart,
or a spade). In the research report, what should the researcher
say about selecting the sample?
 That a random sample of the 50 individuals was taken
 That a wellshuffled deck of cards was used to select the random
sample of the 50 individuals
 In the nexttolast sentence in the top paragraph on page 122, the
claim is made that "you will encounter technical writeups in which
the researchers emphasize ____ to the near exclusion of a clear explanation
of where
their data came from or to whom the results apply."
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