Test Bank for Psychological Data Interpretation
Are samples or populations used in inferential statistics? - Answers Data from samples are used in
inferential statistics to make an inference about the larger population.
If your professor calculated the average grade for your statistics class, would that be considered a
descriptive statistic or an inferential statistic? - Answers The average grade for your statistics class would
be a descriptive statistic because it's being used only to describe the tendency of people in your class
with respect to a statistics grade.
If your professor calculated the average grade for your statistics class and used it to predict something
about how future students might do in statistics, would it be considered a descriptive statistic or an
inferential statistic? - Answers In this case, the average grade would be an inferential statistic because it
is being used to estimate the results of a population of students taking statistics.
Researcher Andrew Gelman wrote about his research in the New York Times: "The average American
knows about 600 people. How do we know this? Researchers led by my Columbia colleague Tian Zheng
posed a series of questions to a representative sample of 1,500 Americans." What is the sample? -
Answers 1,500 Americans
Researcher Andrew Gelman wrote about his research in the New York Times: "The average American
knows about 600 people. How do we know this? Researchers led by my Columbia colleague Tian Zheng
posed a series of questions to a representative sample of 1,500 Americans." What is the population? -
Answers all Americans
Researcher Andrew Gelman wrote about his research in the New York Times: "The average American
knows about 600 people. How do we know this? Researchers led by my Columbia colleague Tian Zheng
posed a series of questions to a representative sample of 1,500 Americans." What is the descriptive
statistic? - Answers The 1,500 Americans in the sample know 600 people, on average.
Researcher Andrew Gelman wrote about his research in the New York Time : "The average American
knows about 600 people. How do we know this? Researchers led by my Columbia colleague Tian Zheng
posed a series of questions to a representative sample of 1,500 Americans." What is the inferential
statistic? - Answers The entire population of Americans has many acquaintances, on average. The
sample mean, 600, is an estimate of the unknown population mean.
What is the difference between discrete and continuous observations? - Answers Discrete observations
can take on only specific values, usually whole numbers; continuous observations can take on a full
range of values.
Three female students complete a Stroop test. Lorna finishes in 12.67 seconds; Desiree finishes in 14.87
seconds; and Marianne finishes in 9.88 seconds. Are these data discrete or continuous? - Answers These
data are continuous because they can take on a full range of values.
,Three female students complete a Stroop test. Lorna finishes in 12.67 seconds; Desiree finishes in 14.87
seconds; and Marianne finishes in 9.88 seconds. Is the variable an interval or a ratio observation? -
Answers The variable is a ratio observation because there is a true zero point.
Three female students complete a Stroop test. Lorna finishes in 12.67 seconds; Desiree finishes in 14.87
seconds; and Marianne finishes in 9.88 seconds. On an ordinal scale, what is Lorna's score? - Answers On
an ordinal scale, Lorna's score would be 2 ( or 2nd).
Eleanor Stampone randomly distributed pieces of paper to students in a large lecture center. Each paper
contained one of three short paragraphs that described the interests and appearance of a female
student. The descriptions were identical in every way except for one adjective. The student was
described as having "short," "mid-length," or "very long" hair. At the bottom of each piece of paper,
Stampone asked the participants (both female and male) to fill out a measure that indicated the
probability that the student described in the scenario would be sexually harassed. What is the nominal
variable used in Stampone's hair-length study? Why is this considered a nominal variable? - Answers The
levels of gender, male and female, have no numerical meaning even if they are arbitrarily labeled 1 and
2.
Eleanor Stampone randomly distributed pieces of paper to students in a large lecture center. Each paper
contained one of three short paragraphs that described the interests and appearance of a female
student. The descriptions were identical in every way except for one adjective. The student was
described as having "short," "mid-length," or "very long" hair. At the bottom of each piece of paper,
Stampone asked the participants (both female and male) to fill out a measure that indicated the
probability that the student described in the scenario would be sexually harassed. What is the ordinal
variable used in the study? Why is this considered an ordinal variable? - Answers The three levels of hair
length (short, mid-length, and very long) are arranged in order, but we do not know the magnitude of
the differences in length.
Eleanor Stampone randomly distributed pieces of paper to students in a large lecture center. Each paper
contained one of three short paragraphs that described the interests and appearance of a female
student. The descriptions were identical in every way except for one adjective. The student was
described as having "short," "mid-length," or "very long" hair. At the bottom of each piece of paper,
Stampone asked the participants (both female and male) to fill out a measure that indicated the
probability that the student described in the scenario would be sexually harassed. What is the scale
variable used in the study? Why is this considered a scale variable? - Answers The distances between
probability scores are assumed to be equal.
The ___ variable predicts the ___ variable. - Answers Independent; dependent
A researcher examines the effects of two variables on memory. One variable is beverage (caffeine or no
caffeine) and the other is the subject to be remembered (numbers, word lists, aspects of a story).
Identify the independent and dependent variables. - Answers There are two independent variables:
beverage and subject to be remembered. The dependent variable is memory.
, A researcher examines the effects of two variables on memory. One variable is beverage (caffeine or no
caffeine) and the other is the subject to be remembered (numbers, word lists, aspects of a story). How
many levels do the variables "beverage" and "subject to be remembered" have? - Answers Beverage has
two levels: caffeine and no caffeine. The subject to be remembered has three levels: numbers, world
lists, and aspects of a story.
Kiho Kim and Stevia Morawski studied 360 students in a university cafeteria, measuring how much food
students wasted. The researchers compared waste among students when trays were available to waste
among students when trays were not available. They found that students wasted 32% less food when
trays were not available. What is the independent variable in this study? - Answers Whether or not trays
were available
Kiho Kim and Stevia Morawski studied 360 students in a university cafeteria, measuring how much food
students wasted. The researchers compared waste among students when trays were available to waste
among students when trays were not available. They found that students wasted 32% less food when
trays were not available. What are the levels of the independent variable? - Answers Trays were
available; trays were not available.
Kiho Kim and Stevia Morawski studied 360 students in a university cafeteria, measuring how much food
students wasted. The researchers compared waste among students when trays were available to waste
among students when trays were not available. They found that students wasted 32% less food when
trays were not available. What is the dependent variable? Suggest at least one way in which Kim and
Morawski might have measured this. - Answers Food waste; food waste could have been measured via
volume or weight as it was thrown away.
Kiho Kim and Stevia Morawski studied 360 students in a university cafeteria, measuring how much food
students wasted. The researchers compared waste among students when trays were available to waste
among students when trays were not available. They found that students wasted 32% less food when
trays were not available. What would it mean for the food waste measure to be reliable? - Answers The
measure of food waste would be consistent over time.
Kiho Kim and Stevia Morawski studied 360 students in a university cafeteria, measuring how much food
students wasted. The researchers compared waste among students when trays were available to waste
among students when trays were not available. They found that students wasted 32% less food when
trays were not available. What would it mean for the food waste measure to be valid? - Answers The
measure of food waste was actually measuring how much food was wasted.
How do the two types of research discussed - experimental and correlational - differ? - Answers
Experimental research involves random assignment to conditions; correlational research examines
associations where random assignment is not possible and variables are not manipulated.
How does random assignment help to address confounding variables? - Answers Random assignment
helps to distribute confounding variables evenly across all conditions so that the levels of the
independent variable are what truly vary across groups or conditions.
