BIOSTATISTICS Flashcards
TYPES OF VALIDITY
-internal
-external
The extent to which a
study establishes a
trustworthy
cause-and-effect
relationship between a
treatment and an
outcome
INTERNAL VALIDITY
Refers to how well the
outcome of a study can
be expected to apply to
other settings.
EXTERNAL VALIDITY
example of internal validity
methodology
example of external validity
results and
conclusion
Gives information that describes the data in some
manner
DESCRIPTIVE STATISTICS
T/f: Data is also described by compiling it into a graph,
table or other visual representation.
True
Uses a random sample of data taken from a large
population to describe and make inferences about
the population
INFERENTIAL STATISTICS
Analyze the sample to generalize the whole using
statistical tools
INFERENTIAL STATISTICS
From a population, you
get a sample to describe.
DESCRIPTIVE STATISTICS
When you represent the
population using a sample
to make a conclusion on
the population.
INFERENTIAL
STATISTICS
The smallest numbers
that can actually belong
to different classes
LOWER CLASS LIMITS
The largest numbers
that can actually belong
to different classes
UPPER CLASS LIMITS
Are the numbers used to separate classes, but
without the gaps created by class limits.
CLASS BOUNDARIES
MEASUREs OF CENTRAL TENDENCY
MEAN, MEDIAN, MODE
T/F: The disadvantage of using the mean as a measure
is that IT IS SENSITIVE TO UNUSUAL VALUES
MEAN
defined as the point in the distribution with 50% of
the measure on each side of it.
MEDIAN
Midpoint of the distribution
Median
T/f: Median is Not affected by extreme values
True
Value that appears most or most occurring value
Mode
T/F: Mode is Not affected by extreme values
True
Disadvantage of mode
difficult to use in a small sample of
continuous data
If there is one pea
UNIMODAL
If there are two peaks
BIMODAL
Simplest measure of variation
● Difference between the largest and the smallest
observations
RANGE
Average of squared deviations of values from the
mean
VARIANCE
How far each number from the data set is from the
mean
Variance
Heterogeneity or homogeneity among samples and Heterogeneity or homogeneity among samples
STANDARD DEVIATION
STANDARD DEVIATION unit follows that of
mean
How far the data set is from the mean
STANDARD DEVIATION
Shows variation relative to mean
COEFFICIENT OF VARIATION (CV)
Coefficient of Variation
(SD/mean) X 100
std dev =
square root of variance