Chapter 18 Experimental Design and Data Handling

Question 1

Blind assessment is an effective method of avoiding bias.

Answer 1

True

Question 2

When a sample group shows no effect, although the treatment would actually have a real effect on the whole population, the study has produced false positive results.

Answer 2

False

Question 3

Scientific research begins with a conclusion about a set of animals or humans.

Answer 3

False

Question 4

A group of test subjects in a research study is used as a sample to draw conclusions about an entire population.

Answer 4

True

Question 5

If results from a study can be replicated in some animal studies but not in others, the study lacks:

Answer 5

generality

Question 6

An experimental hypothesis is a BLANK of the results of the study.

Answer 6

prediction

Question 7

An experimental hypothesis is a statement of the answer an investigator expects to find to a research question.

Answer 7

True

Question 8

In a study that attempts to determine if using treats to elicit a desired behavior (move through a tunnel to a new cage) helps the rat learn the behavior more quickly, what is the dependent variable?

Answer 8

Time taken to reach new cage

Question 9

Confounding variables are known as:

Answer 9

non-experimental variables

Question 10

All members of the research team have a responsibility to see that the study protocol is followed exactly as written and approved by the IACUC.

Answer 10

True

Question 11

Unexpected differences within the subjects can be controlled by:

Answer 11

randomization

Question 12

The independent variable is the variable that is measured during the study.

Answer 12

False: it is the variable that is manipulated by the investigator.

Question 13

The BLANK is the number of experimental units in a group.

Answer 13

sample size.

Question 14

In a study that attemps to determine if using treats such as pieces of carrots to elicit a desired behavior in rats (move through a tunnel to a new cage) will help the rats learn the behavior more quickly, what is the independent variable?

Answer 14

The treats

Question 15

In a scientific study, the control group is the group receiving the experimental treatment.

Answer 15

False

Question 16

Some sources of nonexperimental variation cannot be controlled.

Answer 16

True

Question 17

In any scientific study, the goal is to include as many animals as possible in each group.

Answer 17

False

Question 18

Two studies demonstrated that Drug A reduces joint inflammation in baboons. Study 1 shows a significant difference between the experimental and the control group at p = 0.10, and Study 2 shows a significant difference at p = 0.01. Which study has the greater confidence level?

Answer 18

Study 2

Question 19

What term is used for the measure of dispersion of data?

Answer 19

Standard deviation

Question 20

In a normal distribution, 95% of the measurements fall between the mean plus or minus one standard deviation (mean +/- SD)

Answer 20

False: 68%, then 95% and then 99%

Question 21

In statistics, the p-value is the opposite of the confidence level.

Answer 21

True

Question 22

Information based on reported examples is known as:

Answer 22

anecdotal

Question 23

If an article states that the results show a significant difference at the 0.05 level, what does this mean?

Answer 23

There is a 95% probability that the difference is real.

Question 24

A graph with a curve encompassing a wider span across the x-axis indicates greater:

Answer 24

variability

Question 25

The Research question is usually expressed as a(n):

Answer 25

Hypothesis

Question 26

A study attempts to determine if using treats, such as chocolate chips, elicits a desired behavior in rats of moving through a tunnel to a new cage and helps the rats learn the behavior quicker. What is the independent variable?

Answer 26

The treats

Question 27

Statistics is a science that deals with the BLANK, BLANK, BLANK, and BLANK of data by the use of BLANK.

Answer 27

collection, classification, analysis, interpretation, probability theory

Question 28

What criteria should be used in determining the number of animals to be used in a study?

Answer 28

The 3Rs principle, The confidence level selected

Question 29

Dependent variable

Answer 29

The variable that is measured during the study

Question 30

Independent variable

Answer 30

The variable that is being manipulated by the investigator.

Question 31

Control group

Answer 31

A similar group of animals that does not receive the experimental treatment

Question 32

Treatment group

Answer 32

The animals that receive the experimental treatment

Question 33

Name a statistical method that helps control variables by eliminating personal bias from the study

Answer 33

Randomization

Question 34

For a sample that has a normal distribution, 95% of the data points will fall within +/- 2 SD

Answer 34

True

Question 35

What is the difference between the confidence value and the p-value?

Answer 35

An index of certainty that the difference is due to the experimental treatment.

Question 36

What is the factor controlled by randomization?

Answer 36

Bias

Question 37

Experimental Hypothesis

Answer 37

a prediction of the results of the study; it is a statement of the answer the investigator expects to find to the research question.

Question 38

Null Hypothesis

Answer 38

states that there is no difference between the means of two groups; that is, the treatment has no effect on the dependent variable

Question 39

What is NOT a common originating source for a research question?

Answer 39

A science textbook

Question 40

A(n) __________ is an assumption evaluated by research.

Answer 40

hypothesis