- Description
PSY 245 Wk 4 – Concept Check
- Question 1
1/1
A researcher conducts an experiment in which she assigns participants to one of two groups, which she exposes to different doses of a particular drug. She then gets the participants to learn a list of 20 words and two days later sees how many they can recall. In the experiment, the dependent measure is simply the number of words recalled by each participant.
What type of dependent measure is this?
Nominal
Ordinal
Interval
Ratio
None of the above
- Chapter 8: “Examining Differences Between Means: The t-test”
- Question 2
Which of the following statements is/are true about the t-distribution?
Its shape changes with the number of degrees of freedom.
Its expected value is 0.
It can be used to test differences between means if the population standard deviation is known.
Both a and b
- Chapter 9: “Examining Relationships Between Variables: Correlation”
- Question 3
1/1
As part of a psychology assignment, Kate has to calculate Pearson’s r to measure the strength of association between two variables. She finds that r = −.2 and that this is significant at her selected alpha level of .05. What should she conclude?
There is a significant but small relationship between the two variables.
There is a non-significant but large relationship between the variables.
There is a significant and moderate relationship between the variables.
The two variables are unrelated.
Variation in one variable is associated with most of the variation in the other.
- Question 4
1/1
The correlational fallacy refers to which of the following ideas?
Correlation can be statistically significant without being psychologically meaningful.
A strong correlation between variables does not mean that one predicts the other.
Correlation between variables does not mean that one variable is responsible for variation in the other.
Correlation does not justify prediction.
- Question 5
1/1
Which of the following statements is true of the problem of restricted range?
Restricted range can reduce the size of correlations.
Restricted range can lead to a violation of the assumption of bivariate normality.
Restricted range can produce regression to the mean.
All of the above
Answers a and b only
- Question 6
1/1
“A graph plotting the scores on one variable against the scores on another.”
What type of graph does this describe?
A line graph
A bar graph
A scatterplot
An angiogram
A scattergram
- Question 7
1/1
“A measure of the degree of linear association between two variables.”
Which term best fits this definition?
Correlation coefficient
Covariance coefficient
Covariance
Product-moment coefficient
Linear coefficient
- Question 8
1/1
“The amount of variation in one variable associated with variation in another variable (or variables). In the bivariate case, this is given by r2.”
Which term best fits this definition?
Variance
Covariance
Common variance
Linear correlation
Estimated variance
- Chapter 10: “Comparing Two or More Means by Analysing Variances: ANOVA”
- Question 9
Which of the following statements is false?
One difference between ANOVA and t-tests is that ANOVA allows researchers to compare responses of more than two groups.
One difference between ANOVA and t-tests is that ANOVA does not make assumptions about homogeneity, normality, and independence.
One difference between ANOVA and t-tests is that ANOVA can be used to simultaneously examine the impact of more than one variable.
One difference between ANOVA and t-tests is that ANOVA is based on analysis of the ratios of variances.
One difference between ANOVA and t-tests is that ANOVA uses two separate degrees of freedom (one for between-cells variance, one for within-cells variance).
- Chapter 11: “Analysing Other Forms of Data: Chi-square and Distribution-free Tests”
- Question 10
A team of researchers conducts a large study examining factors that predict poor health in the workplace. They find that more men than women have heart attacks at work. They plan to analyze their data using a binomial test, but are aware of the need to take into account relevant base-rate information.
Which of the following constitutes relevant base-rate information for this purpose?
The proportion of people in the workplace who are men
The proportion of people in the workplace who have heart attacks
The proportion of men in the workplace who have heart attacks
The proportion of women in the workplace who have heart attacks
None of the above; base-rate information is irrelevant in this study