Quiz (Chapter 6)
Estimation
Introduction
 The two main types of estimation are called _______ estimation and
_______ estimation.
 (T/F) When a researcher uses the techniques of estimation, he/she
is making a guess as to unknown characteristics of the sample based
upon the known characteristics of the population.
Sampling Error
 What is a "sampling error"?
 If a population is made up of 600 males and 400 females, should you
expect that a simple random sample of 100 people will end up containing
60 males and 40 females?
 Can researchers prevent sampling errors by extracting stratified
random samples from populations?
 Under what 2 unrealistic conditions would a researcher be justified
in anticipating no sampling error?
Sampling Distributions and Standard Errors
 If 100 samples are taken from a population, with each sample having
n = 25, there would be __ entries in the sampling distribution of means
if the sample means are plotted.
 Which of the following terms is closest in meaning to the term "standard
error?"
 computational error
 sampling error
 standard score
 standard deviation
 Suppose 10,000 random samples of the same size are drawn from a population
having M=50 & SD=4. Each sample's mean is computed and then
displayed in a sampling distribution. About ___% of the sample
means would lie within one standard error of 50?
 1/4
 1/3
 1/2
 2/3
 3/4
 In the expression SEM, the E stands for "error." What do the
S and the M stand for?
 (T/F) Only 1 word can legitimately be put in the blank in the phrase:
"standard error of the ____"
 In Excerpt 6.2, did women or men have the larger estimated standard
error for the age they started gambling?
 (T/F) In Excerpt 6.3, the estimated standard error of the means
are equal to the heights of the white and gray bars.
Confidence Intervals: What They Look Like
 In Excerpt 6.8, how many confidence intervals are presented?
 If a researcher computes a sample mean and says "95% CI = (8090),"
could the sample mean be 95?
 (T/F) Confidence intervals can be built for means & correlation
coefficients but not for percentages.
 If the CIs presented in Excerpts 6.66.9 are typical, what is the
most popular level of confidence used?
The Construction of Confidence Intervals
 In building a confidence interval, what does a researcher specify
first?
 the two numerical values that define the interval
 the level of confidence desired
 (T/F) Using the same data, a confidence interval will get wider if
the confidence level is increased.
 A __________ relationship exists between the size of the sample &
the distance between the end points of the confidence interval.
 positive
 negative
 near zero
 absolutely zero
 If based on the same 25 scores, will a 95% CI for the mean turn out
the same as a 95% CI for the median?
The Proper Interpretation of Confidence Intervals
 (T/F) A confidence interval indicates the probability that
the population parameter lies somewhere between the numerical end points
of the CI.
 (T/F) To interpret a CI correctly, you must imagine that lots
of samples are drawn from the population.
The Advantage of Confidence Intervals Over Estimate Standard Errors
 Confidence intervals are more easily interpreted than "standard error
intervals" because CIs take into consideration __ whereas "standard
error intervals" do not.
 sampling error
 N
 n
 When does the advantage of confidence intervals over "standard error
intervals" become trivial?
Point Estimation
 When a researcher engages in point estimation, does he/she stipulate
a confidence level?
 What statistical concept can be used to explain why point estimation
is unlikely to "hit the bullseye?"
 Should reliability and validity coefficients be considered to be
point estimates?
 (T/F) Point estimation should be respected because it is used twice
whenever CIs are built.
Warnings Concerning Interval and Point Estimation
 (T/F) If someone says "52 ± 3," the 3 might be referring
to the SD or it might be referring to the SEM.
 (T/F) If a researcher carefully puts his/her sample data into
the proper formula, he/she will still be unable to determine
the precise value of the standard error of the statistic being focused
on.
 (T/F) If a confidence interval is built around a correlation
coefficient, it may be the case that the CI's end points are not the
same distance from the numerical value of r computed from the sample
data.
 The 2nd sentence in the final paragraph of Chapter 6 says that "the
entire process of estimation requires that the data used to form the
inference come from _____ ."
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