Communication Research: Asking Questions, Finding Answers, 5e (Keyton)
Chapter 9 Descriptive Statistics, Significance Levels, and Hypothesis Testing
1) The normal curve is:
A) a theoretical distribution of scores.
B) characterized by the majority of cases at one end of the curve.
C) asymmetrical.
D) characterized by very few very high or very few very low scores.
E) the distribution of participants’ scores for all variables.
2) A skewed curve is:
A) symmetrical.
B) characterized by identical left and right slopes.
C) characterized by the mean, median, and mode in the same location.
D) characterized by the data being bunched to one side or the other.
E) a theoretical distribution of scores.
3) The mean:
A) is the most commonly reported measure of central tendency.
B) is the most sensitive to extremely high or low scores.
C) depends upon each and every score.
D) is also known as the average.
E) all of the above.
4) The standard deviation is the:
A) lowest score given by any participant.
B) indication of how close or how far apart scores are from one another.
C) computation found by adding all scores and dividing by the number of cases.
D) computation found by subtracting the lowest score from the highest score.
E) score reported most often by participants.
5) The further out a score is on the distribution, the:
A) more skewed the score.
B) more common the score.
C) more extreme the score.
D) more normal the score.
E) more likely the score will fall beyond the +/-4 deviation.
6) A frequency is used to:
A) indicate the mode of the scores.
B) assess the dispersion of the scores.
C) report on the occurrence of communication events.
D) compute percentages.
E) C and D.
7) A significance level is:
A) the degree to which research findings have utility.
B) the degree to which the sample mirrors the population.
C) the term used to described research that has social significance.
D) the level of error the researcher is will to accept for each statistical test.
E) based solely on sample size.
8) Hypothesis testing:
A) relies on sampling and significance levels.
B) is really decision making about accepting the alternative explanation or retaining the null
hypothesis.
C) allows for Type I and Type II error.
D) is used in research projects based on quantitative methods.
E) all of the above.
9) Choose the research term that describes “the null hypothesis is retained even though the null
hypothesis is false.”
A) Type I Error
B) Type II Error
10) Choose the research term that describes “the null hypothesis is rejected even though the null
hypothesis is true.”
A) Type I Error
B) Type II Error
11) Choose the research term that describes “the researcher claims some difference or relationship
exists when one does not.”
A) Type I Error
B) Type II Error
12) Choose the research term that describes “researcher misses claiming a difference or
relationship that is real.”
A) Type I Error
B) Type II Error
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Match the following terms and descriptions:
A) Data
B) Dataset
C) Inferential statistics
D) Raw data
E) Descriptive statistics
13) Information about communication phenomena, of which numbers are one type
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14) Participants’ numerical responses to questionnaire
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15) Summary information about the data set as a whole
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16) Information about the relationships between or among variables
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17) All participants’ responses compiled together
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Match the following terms and descriptions:
A) Number of cases
B) Measures of central tendency
C) Measures of dispersion
18) Number of sources from which data were collected
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19) Describes the spread of scores
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20) Describe how the majority of participants responded
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21) Generally, it is not meaningful to analyze or interpret a score on one variable from one
individual.
22) A negatively skewed curve represents a distribution in which there are very few scores on the
right side of the distribution.
23) In a skewed distribution, the mean is always pulled to the side with the long tail.
24) Descriptive statistics supply information about the variables, but the researcher must make
value judgments or inferences about what the data mean.
25) The letter n or N represents the number of cases for which data is reported.
26) Mean, median, and mode are measures of central tendency.
27) To compute the median, the data must be arranged in order from lowest to highest score.
28) Most distributions of scores have only one score that occurs most often.
29) Two distributions of scores can have the same mean, but different spreads of scores.
30) In considering the distribution of scores, there are four standards to the right of the midpoint,
and four standards to the left of the midpoint.
31) All percentages are computed on 100 as the base.
32) A significance level of .05 means that 5 out of 100 findings that appear to be valid will, in fact,
be due to chance.
33) Significance levels are never set at levels other than .05.
34) Achieving statistical significance indicates that the findings have social and practical
application.
35) How does a normal curve differ from a skewed curve?
36) Explain why researchers should examine their data for its normal or skewed characteristics.
37) Describe the role of the researcher versus the use of statistical programs in calculating and
interpreting descriptive statistics.
38) Explain why reporting only the mean of a variable is insufficient.