Biostatistics

A dental sales representative describes the strength of a new ceramic material in Newtons/m². This is an example of what type of variable?

Continuous

Which of the following epidemiological studies provides a temporal relationship between exposure and disease?

Cohort

The bacteria from different necrotic root canal systems are cultured for a research study. Histological analysis confirms that a large percentage (80%) of the results of the culture are correct. What type of measurement does this analysis demonstrate?

Accuracy

What does sensitivity refer to

True positive among people with the disease

How does the width of a confidence interval change as sample size increases and standard deviation decreases, respectively?

Decrease, decrease

What is a type 2 error

When one fails to reject a null hypothesis that is actually false

What is a type 1 error

When one rejects a null hypothesis that is actually true

A researcher is comparing the mean probing depth between smokers and nonsmokers. Probing depth is recorded as a continuous variable, and the data are approximately normally distributed. Which statistical test is most appropriate to compare the two means?

t-test (determines if the average value of a continuous variable differs between 2 groups)

The cariogenic potential as measured by carbohydrate clearance time of three different sodas was evaluated. Subjects are randomly assigned to one of the three soda groups, and their salivary glucose concentration is recorded 1 minute after consumption. This is an example of what type of data structure?

Unpaired (data that is being compared from different individuals)

The bacterial species cultured in a root canal system is demonstrating consistent results over repeated trials. What does this demonstrate?

Reliability