Chapter 18 Experimental Design and Data Handling Flashcards
Blind assessment is an effective method of avoiding bias.
True
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.
False
Scientific research begins with a conclusion about a set of animals or humans.
False
A group of test subjects in a research study is used as a sample to draw conclusions about an entire population.
True
If results from a study can be replicated in some animal studies but not in others, the study lacks:
generality
An experimental hypothesis is a BLANK of the results of the study.
prediction
An experimental hypothesis is a statement of the answer an investigator expects to find to a research question.
True
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?
Time taken to reach new cage
Confounding variables are known as:
non-experimental variables
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.
True
Unexpected differences within the subjects can be controlled by:
randomization
The independent variable is the variable that is measured during the study.
False: it is the variable that is manipulated by the investigator.
The BLANK is the number of experimental units in a group.
sample size.
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?
The treats
In a scientific study, the control group is the group receiving the experimental treatment.
False
Some sources of nonexperimental variation cannot be controlled.
True
In any scientific study, the goal is to include as many animals as possible in each group.
False
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?
Study 2
What term is used for the measure of dispersion of data?
Standard deviation
In a normal distribution, 95% of the measurements fall between the mean plus or minus one standard deviation (mean +/- SD)
False: 68%, then 95% and then 99%
In statistics, the p-value is the opposite of the confidence level.
True
Information based on reported examples is known as:
anecdotal
If an article states that the results show a significant difference at the 0.05 level, what does this mean?
There is a 95% probability that the difference is real.
A graph with a curve encompassing a wider span across the x-axis indicates greater:
variability
The Research question is usually expressed as a(n):
Hypothesis
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?
The treats
Statistics is a science that deals with the BLANK, BLANK, BLANK, and BLANK of data by the use of BLANK.
collection, classification, analysis, interpretation, probability theory
What criteria should be used in determining the number of animals to be used in a study?
The 3Rs principle, The confidence level selected
Dependent variable
The variable that is measured during the study
Independent variable
The variable that is being manipulated by the investigator.
Control group
A similar group of animals that does not receive the experimental treatment
Treatment group
The animals that receive the experimental treatment
Name a statistical method that helps control variables by eliminating personal bias from the study
Randomization
For a sample that has a normal distribution, 95% of the data points will fall within +/- 2 SD
True
What is the difference between the confidence value and the p-value?
An index of certainty that the difference is due to the experimental treatment.
What is the factor controlled by randomization?
Bias
Experimental Hypothesis
a prediction of the results of the study; it is a statement of the answer the investigator expects to find to the research question.
Null Hypothesis
states that there is no difference between the means of two groups; that is, the treatment has no effect on the dependent variable
What is NOT a common originating source for a research question?
A science textbook
A(n) __________ is an assumption evaluated by research.
hypothesis
