Question 1

When numerical data in descriptive statistics is plotted with a normal curve, which value is the highest?
A)Mean
B)Median
C)Mode
D)None of the above

Accepted Answer

When numerical data in descriptive statistics is plotted with a normal curve, none of these values is the highest.
With a normal curve, all of the values of mean, median and mode are equal. A 'Bell' curve depicts an equal distribution of data.

Question 2

A periodontal probe is used to complete a periodontal exam and determine the presence, location, and severity of periodontal disease. The fact that the disease is diagnosed largely based on the findings of attachment loss demonstrates what important quality?
A)Reliability
B)Validity
C)Sensitivity
D)Specificity

Accepted Answer

The fact that the disease is diagnosed largely based upon the findings of attachment loss demonstrates the quality of validity.
A test is valid if it can be counted upon to measure what it claims to measure. Measuring for attachment loss is recognized as a valid test for the presence of periodontal disease.

Question 3

Which research sampling technique is most prone to bias?
A)Random
B)Systematic
C)Convenience
D)Judgment

Accepted Answer

The judgment research sampling technique is most prone to bias.
If the examiner is too familiar with the population from which study subjects are selected, it would be too easy to pick out individuals who are already known for having circumstances which could help sway study results in the direction the examiner is hoping for.

Question 4

Why is being double-blinded the best way to prevent bias in an experimental study?
A)Two or more of the study subjects don't even know a study is going on
B)Neither the researcher nor the study subjects know who is in which group, whether experimental or placebo
C)The researchers are aware of who is in which group, but the study subjects are not
D)The results of the study cannot be known to anyone until many years later

Accepted Answer

Being double-blinded is the best way to prevent bias in an experimental study because neither the researcher nor the study subjects know who is in which group, whether experimental or placebo.
By being double-blinded, there is no room for skewed human perception to influence the outcome. Some study subjects may be inclined to report results simply from being aware that they should or should not expect results. "Blinded" researchers won't be looking for any particular outcome in the experimental groups.

Quiz 1: Community Health and Research Principles

When numerical data in descriptive statistics is plotted with a normal curve, which value is the highest?

A periodontal probe is used to complete a periodontal exam and determine the presence, location, and severity of periodontal disease. The fact that the disease is diagnosed largely based on the findings of attachment loss demonstrates what important quality?

Which research sampling technique is most prone to bias?

Why is being double-blinded the best way to prevent bias in an experimental study?