What is a way that Sensitivity is defined?

a. 1- Sensitivity

b. 1- False Negative Rate

c. 1-Specificity

d. Unable to determine it numerically

What would it mean for a home pregnancy test (HPT) to have good sensitivity?

a. Means the test likely says youre pregnant when you are

b.Means the test likely says you arent pregnant when you are

c. Means the test likely says youre pregnant when you arent

d. Means the test likely says you arent pregnant when you arent.

Identify the different scenarios in this Drug Test:

Reality-

Identify the different scenarios in this Drug Test:

Test-

Identify the different scenarios in this Drug Test:

Sensitivity-

Identify the different scenarios in this Drug Test:

Specificity-

Identify the different scenarios in this Drug Test:

False Negative-

Identify the different scenarios in this Drug Test:

False Positive-

Identify the different scenarios in this Drug Test:

Which is the worst?

In the context of hypothesis testing, good sensitivity speaks to: 

a. The ability of the test to reject a false HO

b. The ability of the test to be very specific about what it is testing for

c. The ability of the test to reject an HO that is true

d. The ability of the test to not reject an HO that is true

If we are testing the null hypothesis HO:p<0.90 versus HA: p>0.90 and we compute z to be 1.8, then:

a. we have statistically significant results, with an estimated false positive rate that is less than 0.05

b. we fail to have statistically significant results, with an estimated false positive that is less than 0.05

c. we have convincing evidence that p is >.90

d. we fail to have convincing evidence that p is >.90

An experiment is done to compare two methods of instruction, Method A and Method B. At the end of the experiment a statistian reports that if one rejects the hypothesis that the two methods are the same, in favor of the alternative that they are different, then the false positive rate of that rule will be about 2 in 100. This means:

a. You can be certain the methods are different

b. you can be certain the methods are not different

c. The methods are probably different

d. The methods are probably not different

A given test is known to have a sensitivity of 90%. What does this tell you about the specificity?

a. the specificity is 90%

b. The specificity is 10%

c. Not much, the specificity could be anywhere between 5% and 95%

d. Nothing, the specificity could be anything

In general what do you think is preferred for medical screening tests and why?

a. High sensitivity-so patients without the disease can be correctly identified

b. High Sensitivity-so patients with the disease can be correctly identified

c. Low specificity-so patients without the disease can be correctly identified

d. High specificity-so patients with the disease can be correctly identified

Refer to the work we have done with FST data in class.  Suppose you changed your rule to require that the total FST score required you to say you were drunk was 6 or above instead of 2 or above. What will happen to the specificity of your rule?

a. it will increase

b. it will decrease

c. It will stay the same

d. cant predict what will happen

A test for prostate cancer in men is known to have a sensitivity of 97% and a specificity of 95%. If i were to test positive, what would be the probability of me having prostate cancer?

a. 95%

b. 97%

c.<5%

d. Depends on the prevalence of prostate cancer among all males

Refer to the work we have done with field sobriety test data in class. Suppose you changed your rule to require that the total FST score required to say you were drunk was 8 or above instead of 4 or above. What will happen to the specificity of your rule?

a. It increases

b. It decreases

c. It stays the same

d. Can't predict what will happen

In our class this semester, what did we mean when we said the results of a certain test were statistically significant?

a. We meant we had been able to reject HO with a false negative rate that was tolerable ( usually below 0.05)

b. We meant we had been able to reject HA with a false positive rate that was tolerable( usually below 0.05)

c. We meant we had been able to reject HO with a false positive rate that was tolerable( usually below 0.05)

d. We meant we had been able to reject HA with a false negative rate that was tolerable (usually below 0.05)

Which of the following is the correct interpretation of a p-value (with value x)?

a. Given HO is true, there is probability x that we would obtain the data we got or data more extreme

b. Give HA is true, there is probability x that we would obtain the data we got or data more extreme

c. Given HO is true, there is probability 1-x that we would obtain the data we got or data more extreme

d. Given HA is true, there is a probability 1-x that we would obtain the data we got or data more extreme

In words specificity is:

a. The ability to correctly identify true positives

b. The ability to correctly identify true negatives

c. The ability to incorrectly identify true positives

d. The ability to incorrectly identify true negatives

In this situation, the 700 new mothers form the

a. population

b. sample

c.statistic

d. parameter

In this situation, the percentage of all US mothers who breastfeed their infants is the

a. population

b. sample

c. statistic

d. parameter

What can one say about the sampling distribution of a sample statistic based on a simple random sample?

a. It is about bell-shaped and peaks above the parameter

b. It is usually skewed if the population is not bell-shaped

c. it is about bell-shaped and peaks above the statistic

d. nothing can be said in advance about the sampling distribution since the sampling was random

A cattle farmer recently bought a new herd of cattle. He was interested in knowing the mean weight of his 35 new cows. When he told his wife that the mean was 1100 pounds, she asked what the margin error was.  The farmer argued that there is no need for one. Who was confused in this case?

a. The wife because no specific confidence level was asked for.

b. The farmer because only sampling variability is present

c. The wife because there is no sample

d. The farmer because he never took a stats class

Which of the following sources of error is addressed by the margin of error?

a. sampling variability that comes from choosing a random sample

b. errors in entering the data into the computer

c. errors because some of the subjects did not understand the questions

d. biases due to voluntary response

What is the purpose of a push poll?

a. To spread negative information

b. To see what kind of MOE will result

c. To get quick results

d. To see what kinds of themes and packages move the public

I want to take a random sample of this Stats 210 class. I assign each student a unique number based on their height. I then use a random number generator to pick 20 students. This is a random sample.

a. True. As long as i dont ask a question about height, it is random

b. True. Every possible sample had the same chance of being selected

c. False. Some students were more likely than others to be selected, depending on their height.

d. False. I should sample from the entire university

I want to take a random sample of this Stats 210 class. I assign each student that came to class last tuesday a number and use a random number generator to select 20 students. This is a random sample

a. True. I used a random number generator.

b. True. Every possible sample had the same chance of being selected

c. False. There was coverage error since not all students attended class.

d. False. Some students were more likely than others to be selected, depending on their height

Inference- 

The act of drawing conclusions about something we cannot know for sure based on information we have to assume is accurate.

Confounding- 

can compromise the worth of our inferences 

Response variable- 

variable measuring in experiment 

Explanatory variable- 

what you change or alter

Lurking Variable- 

Variable not directly studied that can compromise your ability to attribute any changes in the response to a treatment 

Positive association- 

upward to right.

Negative association- 

downward to right

What constitutes a random sample? 

Everyone has an equal chance to take the survey and also the people chosen to take it must be picked at random