Question 1

Why should researchers be cautious about unexpected results in their data-even when those results are statistically significant?

Accepted Answer

The answer of Why should researchers be cautious about unexpected...

Question 2

Which of the following best describes the statistical relationship between people's heights and weights?
A) perfect
B) negative
C) extremely weak
D) positive

Accepted Answer

There is a positive relationship between people's heights and weights, meaning that as one variable (height) increases, the other variable (weight) also tends to increase. However, the relationship is not perfect as there can be some variation in weight even among people of similar heights.

Question 3

Imagine you find an unexpected but statistically significant result in your data. Which of the following courses of action makes the most sense?
A) ignore it
B) immediately write it up for publication
C) follow up on it in a new research study
D) none of the above

Accepted Answer

If an unexpected but statistically significant result is found, the best course of action would be to follow up on it in a new research study. This would help to confirm the findings and potentially lead to new insights or discoveries. Ignoring it or immediately writing it up for publication without further investigation could lead to inaccurate or unreliable conclusions.

Question 4

Which of the following describes Pearson's r?
A) It is the average amount by which the scores in two sets of data differ from each other.
B) It is the cross-product of two variances.
C) It is average difference between X and Y, divided by N.
D) It is the mean cross-product of two sets of z scores.

Accepted Answer

Pearson's r is a measure of the strength and direction of the linear relationship between two variables. It is calculated by finding the mean cross-product of the two sets of standardized variables (z-scores). Therefore, the correct description is D, and none of the other options accurately describe Pearson's r.

Question 5

Give an example of an outlier in a set of data. What are at least two ways that you could deal with this outlier?

Accepted Answer

The answer of Give an example of an outlier in...

Question 6

What is standard term for data that have been collected but not yet organized and analyzed?
A) unorganized data
B) preliminary data
C) raw data
D) convenience data

Accepted Answer

Raw data refers to data that have been collected but have not yet been processed or analyzed in any way. It has not been organized, cleaned, or modified in any way. It is the initial stage of data collection and provides a basis for analysis.

Question 7

Pearson's r is NOT appropriate for which of the following?
A) negative relationships
B) nonlinear relationships
C) weak relationships
D) extremely strong relationships

Accepted Answer

Pearson's r is appropriate for linear relationships only, and therefore not appropriate for nonlinear relationships.

Question 8

Identify two psychological variables that you think are probably statistically related. If you were to collect data on this relationship, which measure of relationship strength (d or r) would you use to describe it? What value of d or r would you expect and why?

Accepted Answer

The answer of Identify two psychological variables that you think...

Question 9

In a typical computer data file, which of the following is generally true?
A) Each column is labeled.
B) Each variable is represented by one or more columns.
C) Each participant is represented by one row.
D) all of the above

Accepted Answer

In a typical computer data file, each column is usually labeled, each variable is represented by one or more columns, and each participant is represented by one row. Therefore, all of the above options are generally true.

Question 10

Explain what Pearson's r is for someone who is not already familiar with statistics.

Accepted Answer

The answer of Explain what Pearson's r is for someone...

Question 11

Restriction of range is likely to be a problem in which of the following studies?
A) a study on the relationship between extroversion and risk seeking among college students
B) a study on the relationship between age and attitude toward homosexuality among college students
C) a study on the relationship between extroversion and leadership ability among the employees of a large corporation
D) a study on the relationship between income and happiness among New York City residents

Accepted Answer

College students typically fall within a narrow age range, which can limit the variability in age and potentially obscure the true relationship between age and attitudes.

Question 12

Which of the following pairs of variables seems most likely to have a negative relationship?
A) intelligence and grade point average
B) people's heights and weights
C) shyness and number of friends
D) the amount people exercise and how much they enjoy sports

Accepted Answer

A negative relationship implies that as one variable increases, the other tends to decrease. Shyness and the number of friends typically exhibit this pattern, as more shy individuals often have fewer friends.

Question 13

A research methods student conducts a study on the relationship between people's level of extroversion and the number of close friends they have. She computes Pearson's r, which comes out to be - 1.70. Which of the following is most clearly true?
A) The relationship between the two variables is weak.
B) More extroverted people have fewer friends.
C) She ought to use a bar graph to display her results.
D) She made an error in computing Pearson's r.

Accepted Answer

Pearson's r cannot be less than -1 or greater than 1. A negative value of Pearson's r indicates an inverse relationship, but the value of -1.70 suggests a computational error. Therefore, the researcher made an error in computing Pearson's r.

Question 14

Which of the following would fall into the category of "preliminary analyses?"
A) computing Cronbach's alpha for your dependent variables
B) checking for outliers
C) examining the distributions of your dependent variables
D) all of the above

Accepted Answer

Preliminary analyses are the initial steps taken before conducting a statistical analysis. Computing Cronbach's alpha for dependent variables, checking for outliers, and examining the distributions of dependent variables are all examples of preliminary analyses.

Question 15

Which of the following is true of outliers?
A) They must be removed from the data.
B) They must be included in the final analyses.
C) They invalidate the results of a study.
D) Their removal should have a reasonable justification.

Accepted Answer

Outliers should not necessarily be automatically removed from the data, but their removal should have a reasonable justification. Including them in the final analyses or removing them can depend on the specific context and goals of the study. Invalidating the results of a study based solely on outliers is not necessarily accurate, as they can sometimes represent legitimate and meaningful data points.

Question 16

A research methods instructor gives an exam. Assuming this instructor wants the students to do well, would he or she prefer to see a positively skewed distribution of scores or a negatively skewed distribution of scores? Explain why.

Accepted Answer

The answer of A research methods instructor gives an exam....

Question 17

Explain why the median is sometimes a better measure of central tendency than the mean.

Accepted Answer

The answer of Explain why the median is sometimes a...

Quiz 12: Descriptive Statistics

Why should researchers be cautious about unexpected results in their data-even when those results are statistically significant?

Which of the following best describes the statistical relationship between people's heights and weights?

Imagine you find an unexpected but statistically significant result in your data. Which of the following courses of action makes the most sense?

Which of the following describes Pearson's r?

Give an example of an outlier in a set of data. What are at least two ways that you could deal with this outlier?

What is standard term for data that have been collected but not yet organized and analyzed?

Pearson's r is NOT appropriate for which of the following?

Identify two psychological variables that you think are probably statistically related. If you were to collect data on this relationship, which measure of relationship strength (d or r) would you use to describe it? What value of d or r would you expect and why?

In a typical computer data file, which of the following is generally true?

Explain what Pearson's r is for someone who is not already familiar with statistics.

Restriction of range is likely to be a problem in which of the following studies?

Which of the following pairs of variables seems most likely to have a negative relationship?

A research methods student conducts a study on the relationship between people's level of extroversion and the number of close friends they have. She computes Pearson's r, which comes out to be - 1.70. Which of the following is most clearly true?

Which of the following would fall into the category of "preliminary analyses?"

Which of the following is true of outliers?

A research methods instructor gives an exam. Assuming this instructor wants the students to do well, would he or she prefer to see a positively skewed distribution of scores or a negatively skewed distribution of scores? Explain why.

Explain why the median is sometimes a better measure of central tendency than the mean.