Exam 5: Introduction to Hypothesis Testing

Setting the significance level at a very extreme cutoff (such as .001)increases the chances of:

How do you set up a hypothesis testing problem?

Researchers who do not want to take a lot of risk set the significance level lower than .05, such as p < .001. (True or False)

An experimenter was interested in the accuracy of a new type of polygraph (lie detector)test. To test this, a polygraph operator used the machine on a participant who was told ahead of time to lie about some of the questions being asked. In an average situation of this type, the polygraph test is 75% accurate with a standard deviation of 6.5%. With the new machine the operator correctly identified 83.5% of the false responses. Is the accuracy of the new polygraph different from the usual ones? (Use the .05 level.) a. Use the five steps of hypothesis testing. b. Sketch the distributions involved. c. Explain the logic of what you did (be sure your explanation includes the overall logic of hypothesis testing, including each of the five steps).

For the following question(s): A researcher is interested in a new kind of exercise. This new exercise can be done by anyone because it does not require any equipment, and therefore could be potentially beneficial without cost to the person. The researcher is interested in whether this new exercise will reduce the rate of heart attacks in the people who participate in doing it. -What is the "cutoff on the comparison distribution"?

Setting the significance level cutoff at .10 instead of the more usual .05 increases the likelihood of:

Rejecting the null hypothesis when in fact it is true is a(n)__________.

If the null hypothesis is rejected, the researcher can conclude that the results:

What represents the situation in which the null hypothesis is true?

A researcher is interested in the effect of going through a terrorist attack on the attitude of police officers about the goodness of people in New York City. After the attack, police may hold more positive attitudes about people (because of various acts of heroism and altruism exhibited by residents)or more negative attitudes because of negative outcomes (looting and dishonesty after the event). What type of hypothesis should the researcher make?

What are the generally accepted cutoff points (or conventional levels of significance)in hypothesis testing in psychology?

A researcher tests whether there is any difference between how fast people work in the morning versus how fast they work in the evening. What is the NULL hypothesis?

A sample is studied to see if it represents a population (called Population 1)that is different from a known population (called Population 2). The comparison distribution is:

A researcher wants to know if a new type of exercise improves peoples' health. Would this be a one-tailed or two-tailed test and why?

Based on the results of his study, a researcher rejects the null hypothesis because the probability of obtaining his result if the null hypothesis were true is less than 5%. How would this be symbolized?

In hypothesis testing, if the null hypothesis is rejected, this is taken as support for the __________.

Conventional levels of significance have been set at 5% and 1% in order to:

You want to know if a new employee incentive program really works. How would you test the hypothesis that it does work?

What is a correct argument for using a two-tailed test even if there is a clear basis for predicting a result in a given direction?

A researcher tests effects of a new training program. The hypothesis that this new training program will work better than the old training program is called the: