EBM Final Exam Review UPDATED
ACTUAL QUESTIONS AND CORRECT
ANSWERS
What is statistical inference? - CORRECT ANSWER Using sampled data to make
conclusions about a specific population
As the population size increases what will the mean of the study population approximate? -
CORRECT ANSWER the actual population
Explain Random sampling. - CORRECT ANSWER Every member of the population
meeting the study inclusion/exclusion criteria has an
equal chance of being in the study
Explain cluster sampling. - CORRECT ANSWER Obtain random samples from certain
natural groupings (example: Obtaining samples from different geographic regions of the
United States)
Explain systematic sampling. - CORRECT ANSWER Select a random individual, then
select every nth individual after that in a list of
subjects
Explain convenience sampling. - CORRECT ANSWER Selecting a population based
on the convenience of the investigator (example: physician's office patients, students in a
class)
What does the null hypothesis prove if accepted? - CORRECT ANSWER that there is
no difference between groups
What does the alternative hypothesis prove if accepted? - CORRECT ANSWER that a
difference exists between groups
,Explain one-tailed hypothesis testing. - CORRECT ANSWER Directional Test
(superiority test)
Must be to prove that one is better than the other
Group 1 > Group 2
Explain two-tailed hypothesis testing. - CORRECT ANSWER Nondirectional test
Doesn't mean one is better or worse
Group 1 ≠ Group 2
**More common in literature**
What is Type I error? - CORRECT ANSWER The statistical test used causes the
researcher to reject the null hypothesis, stating a statistically significant difference exists, but
the null
hypothesis is true
What is Type I error also known as? - CORRECT ANSWER False positive
What is Type I error related to and what is its definition? - CORRECT
ANSWER Relates to alpha (a)
alpha: the probability of rejecting the null hypothesis when it is true
What is Type 2 error? - CORRECT ANSWER The statistical test used causes the
researcher to accept the null hypothesis, stating a statistically significant difference does not
exist, but the null hypothesis is false
What is Type 2 error also known as? - CORRECT ANSWER False negative
What is Type II error related to and what is its definition? - CORRECT
ANSWER Relates to beta (B) and Power
, Power:Power=Ability to detect a difference in the outcome between the intervention and
control groups when a difference actually exists
What does power equal? - CORRECT ANSWER 1-Beta
What can lower the chance of Type 2 error? - CORRECT ANSWER A bigger sample
size (they are inversely related)
What power is considered statistically adequate? - CORRECT ANSWER 0.8 (Beta =
0.2)
What is considered worst: false negative or false positive? - CORRECT
ANSWER False positive
When should alpha and beta be determined? - CORRECT ANSWER A priori:
determing prior to the study
What does post hoc mean? - CORRECT ANSWER determined after study is
completed
What is post hoc analysis? - CORRECT ANSWER analysis conducted after the study
is completed based on a pre-determined finding
When do you reject the null hypothesis? - CORRECT ANSWER when the p-value is
less than the alpha level
Does a smaller P-value mean that a result is more statistically significant than a larger? -
CORRECT ANSWER no
What is an Confidence Interval? - CORRECT ANSWER A range of numbers likely to
contain the population interval
ACTUAL QUESTIONS AND CORRECT
ANSWERS
What is statistical inference? - CORRECT ANSWER Using sampled data to make
conclusions about a specific population
As the population size increases what will the mean of the study population approximate? -
CORRECT ANSWER the actual population
Explain Random sampling. - CORRECT ANSWER Every member of the population
meeting the study inclusion/exclusion criteria has an
equal chance of being in the study
Explain cluster sampling. - CORRECT ANSWER Obtain random samples from certain
natural groupings (example: Obtaining samples from different geographic regions of the
United States)
Explain systematic sampling. - CORRECT ANSWER Select a random individual, then
select every nth individual after that in a list of
subjects
Explain convenience sampling. - CORRECT ANSWER Selecting a population based
on the convenience of the investigator (example: physician's office patients, students in a
class)
What does the null hypothesis prove if accepted? - CORRECT ANSWER that there is
no difference between groups
What does the alternative hypothesis prove if accepted? - CORRECT ANSWER that a
difference exists between groups
,Explain one-tailed hypothesis testing. - CORRECT ANSWER Directional Test
(superiority test)
Must be to prove that one is better than the other
Group 1 > Group 2
Explain two-tailed hypothesis testing. - CORRECT ANSWER Nondirectional test
Doesn't mean one is better or worse
Group 1 ≠ Group 2
**More common in literature**
What is Type I error? - CORRECT ANSWER The statistical test used causes the
researcher to reject the null hypothesis, stating a statistically significant difference exists, but
the null
hypothesis is true
What is Type I error also known as? - CORRECT ANSWER False positive
What is Type I error related to and what is its definition? - CORRECT
ANSWER Relates to alpha (a)
alpha: the probability of rejecting the null hypothesis when it is true
What is Type 2 error? - CORRECT ANSWER The statistical test used causes the
researcher to accept the null hypothesis, stating a statistically significant difference does not
exist, but the null hypothesis is false
What is Type 2 error also known as? - CORRECT ANSWER False negative
What is Type II error related to and what is its definition? - CORRECT
ANSWER Relates to beta (B) and Power
, Power:Power=Ability to detect a difference in the outcome between the intervention and
control groups when a difference actually exists
What does power equal? - CORRECT ANSWER 1-Beta
What can lower the chance of Type 2 error? - CORRECT ANSWER A bigger sample
size (they are inversely related)
What power is considered statistically adequate? - CORRECT ANSWER 0.8 (Beta =
0.2)
What is considered worst: false negative or false positive? - CORRECT
ANSWER False positive
When should alpha and beta be determined? - CORRECT ANSWER A priori:
determing prior to the study
What does post hoc mean? - CORRECT ANSWER determined after study is
completed
What is post hoc analysis? - CORRECT ANSWER analysis conducted after the study
is completed based on a pre-determined finding
When do you reject the null hypothesis? - CORRECT ANSWER when the p-value is
less than the alpha level
Does a smaller P-value mean that a result is more statistically significant than a larger? -
CORRECT ANSWER no
What is an Confidence Interval? - CORRECT ANSWER A range of numbers likely to
contain the population interval
