Biostats 100A UPDATED Exam Questions
and CORRECT Answers
statistics - CORRECT ANSWER - branch of science that deals with drawing inferences
from samples to populations
double-blind - CORRECT ANSWER - experimenters and individual both don't know what
is given or gave to control BIAS
margin of error - CORRECT ANSWER - statistical uncertainty, uncertainty in Confidence
Interval estimate (half the width of interval)
sampling - CORRECT ANSWER - sample should be representative of the population, has
statistics
population - CORRECT ANSWER - has parameters
simple random sampling - CORRECT ANSWER - every element of the population has
chance of being selected
random sample - CORRECT ANSWER - probability sample
stratified randomization - CORRECT ANSWER - separate based on covariates (age,
gender, etc.), covariates could affect data, within strata is homogeneous, across strata is
heterogeneous, opposite of cluster randomization, independent study groups
block randomization - CORRECT ANSWER - balance measurements in each strata, could
be expensive
, Hawthorne Effect - CORRECT ANSWER - being in an experiment changes your behavior,
not placebo
cluster randomization - CORRECT ANSWER - sample based on geography, within cluster
is heterogeneous, across clusters is homogeneous, opposite of stratified randomization
systematic random sampling - CORRECT ANSWER - starting point is random, beware of
periodicity
population frame - CORRECT ANSWER - database, ex. registry of voters, DMV
non-response bias - CORRECT ANSWER - only people who want to respond will
respond, this affects data
population-based weighting - CORRECT ANSWER - scale measurements according to
their weights in the population, ex. more men responded than women to poll, each man's vote is
weighted only 4/5 of a vote
non-probability sample - CORRECT ANSWER - not every element of population has
chance of being selected, ex. polling, person on the street, clinical research
descriptive statistics - CORRECT ANSWER - 1. graphical format/tabular
2. numerical
3. frequency distribution
percentiles - CORRECT ANSWER - measurement such that X% are at or below
quartiles - CORRECT ANSWER - rank statistics
right skew - CORRECT ANSWER - median<mean, negative skew value
and CORRECT Answers
statistics - CORRECT ANSWER - branch of science that deals with drawing inferences
from samples to populations
double-blind - CORRECT ANSWER - experimenters and individual both don't know what
is given or gave to control BIAS
margin of error - CORRECT ANSWER - statistical uncertainty, uncertainty in Confidence
Interval estimate (half the width of interval)
sampling - CORRECT ANSWER - sample should be representative of the population, has
statistics
population - CORRECT ANSWER - has parameters
simple random sampling - CORRECT ANSWER - every element of the population has
chance of being selected
random sample - CORRECT ANSWER - probability sample
stratified randomization - CORRECT ANSWER - separate based on covariates (age,
gender, etc.), covariates could affect data, within strata is homogeneous, across strata is
heterogeneous, opposite of cluster randomization, independent study groups
block randomization - CORRECT ANSWER - balance measurements in each strata, could
be expensive
, Hawthorne Effect - CORRECT ANSWER - being in an experiment changes your behavior,
not placebo
cluster randomization - CORRECT ANSWER - sample based on geography, within cluster
is heterogeneous, across clusters is homogeneous, opposite of stratified randomization
systematic random sampling - CORRECT ANSWER - starting point is random, beware of
periodicity
population frame - CORRECT ANSWER - database, ex. registry of voters, DMV
non-response bias - CORRECT ANSWER - only people who want to respond will
respond, this affects data
population-based weighting - CORRECT ANSWER - scale measurements according to
their weights in the population, ex. more men responded than women to poll, each man's vote is
weighted only 4/5 of a vote
non-probability sample - CORRECT ANSWER - not every element of population has
chance of being selected, ex. polling, person on the street, clinical research
descriptive statistics - CORRECT ANSWER - 1. graphical format/tabular
2. numerical
3. frequency distribution
percentiles - CORRECT ANSWER - measurement such that X% are at or below
quartiles - CORRECT ANSWER - rank statistics
right skew - CORRECT ANSWER - median<mean, negative skew value
