Chapter 7 - Review Questions Flashcards
Why does the possibility of sampling error present a problem to researchers when inferring a relationship in the population?
What are inferential statistics used for?
What does α stand for, and what two things does it determine?
a) What are the two major categories of inferential procedures? (b) What characteristics of your study determine which category is appropriate for your study? (c) What is a statistical reason for preferring to design a study where you can use parametric procedures?
A researcher obtains sample data showing that participants who wear a pedometer tend to exercise more often than those who do not wear one. What are the two possible statistical explanations for this result?
Some of the children given a new flu vaccine later develop a neurological disease. Parents claim the vaccine caused the disease. What are the two possible statistical explanations for this result?
What does H 0 stand for and what does it communicate?
What does Ha stand for and what does it communicate?
When do you use a one-tailed test? (b) When do you use a two-tailed test?
What does “significant” convey about the results of an experiment?
Why is obtaining significant results a goal of behavioral research?
- In a study we reject H 0 . Which of the following statements are incorrect and why?
(a) “Now we know that H 0 is false.”
(b) “We have proof that our sample mean represents a particular μ .”
(c) “We have proof that the independent variablecauses scores to change as predicted.”
(d) “It is not possible that the difference between X and μ is due to sampling error.”
(e) “We have evidence that the predicted relationship does not exist.”
- In a study we retain H 0 . Which of the following statements are incorrect and why?
(a) “We have proof that the independent variable does not cause scores to change as predicted.”
(b) “We have convincing evidence that the independent variable does not work.”
(c) “We should conclude that there is no relationship in the population.” (d) “We have insignificant results.”
(e) “We have no information about the relationship in the population.”
(f) “The independent variable may work, but we might have sampling error in representing this.”
(a) In plain English, what is the incorrect statement you could make about a relationship when it does not exist in nature?
(b) Which statistical hypothesis says the relationship does not exist?
(c) What is the incorrect decision you can make with this hypothesis?
(d) What is our name for this error?
(e) What is the incorrect statement you could make about a relationship when it does exist in nature?
(f) How do we make an incorrect decision about H 0 when a relationship does exist?
(g) What is our name for this error?
- We ask if the attitudes toward fuel costs of 100 owners of hybrid electric cars ( X = 76) are different from those reported in a national survey of owners of non-hybrid cars ( μ = 65 and σX = 24 ). Higher scores indicate a more positive attitude.
a. What is the predicted relationship here?
b. Is this a one- or a two-tailed test?
c. In words, state the H 0 and the Ha
d. Compute zobt .
e. What is zcrit ?
f. What do you conclude about attitudes here?
g. Report your results in the correct format.
In question 13, what is the probability we made a Type I error? What would be the error in terms of the independent and dependent variables?
What is the probability we made a Type II error? What would be the error in terms of the independent and dependent variables?
(a) In question 14, is it possible we made a Type I error? What would be the error in terms of the independent and dependent variables? (b) Is it possible we made a Type II error? What would be the error in terms of the independent and dependent variables?
Using the independent and dependent variables, describe the experimental hypotheses when we study:
Using the independent and dependent variables, describe the experimental hypotheses when we study:
a. whether the amount of pizza consumed by college students during finals week increases relative to the amount consumed during the rest of the semester,
Using the independent and dependent variables, describe the experimental hypotheses when we study:
b. whether having participants do breathing exercises alters their blood pressure,
Using the independent and dependent variables, describe the experimental hypotheses when we study:
c. whether sensitivity to pain is affected if we increase participants’ hormone levels,
Using the independent and dependent variables, describe the experimental hypotheses when we study:
d. whether frequency of daydreaming decreases when we increase the amount of light in the room.
- For each study in question 17, indicate whether a one- or a two-tailed test should be used and give the H 0 and Ha: Assume we have a one-sample experiment, and the μ of the dependent scores is 50 before we change the independent variable X .
