WGU D772 Statistical Data Literacy: From Data
to Decisions
Population
Entire group of things you want to study (all university students across the US)
Sample
Smaller group selected from the population (1,000 university students selected from different schools
around the US)
Parameter
numerical summary of a population describing characteristics (Average height of adult women in the US)
Statistic
a numerical measurement describing some characteristic of a sample (Average height of 100 adult
women across the US)
Individuals
objects described by a set of data
Variables
Characteristics or measurements we are interested in studying
Quantitive Variables
variables that can be counted or measured
Data
Values of variables
Stratified Sampling
Dividing a population into distinct subgroups based on specific characteristics.
Strata
subgroups within a population that share a common characteristics.
, Proportionate Sample
a sample where the number of individuals selected from each stratum is proportional to the size of the
stratum population. (25% of the high school population is freshman, then 25% of the sample should be
freshman)
Cluster Sampling
Dividing the population into clusters, which are naturally occurring groups like schools, neighborhoods,
or cities.
Systematic Sampling
Selecting every 'nth" individual from a list of the population starting from a randomly chosen point. (List
of 1000 people if you want a sample of 100 the sampling interc=val would be every 10th person is
selected)
Observational Study
Observe and record data without intervention
Sample Survey
Ask individuals to self-report the values of variables.
experiment
Manipulate variables and observe their effects.
Explanatory Variable
Variable believed to cause the change
Response variable
Variable effected
Treatments
Different values of the explanatory variable
Experimental Unit
Single object or individual being measured
Replication
Repeating the experiment with a sufficiently large sample size or reproducing the entire study to
confirm previous findings
Control Group
Group of participants in an experiment who do not receive the experimental treatment.
Blidning
to Decisions
Population
Entire group of things you want to study (all university students across the US)
Sample
Smaller group selected from the population (1,000 university students selected from different schools
around the US)
Parameter
numerical summary of a population describing characteristics (Average height of adult women in the US)
Statistic
a numerical measurement describing some characteristic of a sample (Average height of 100 adult
women across the US)
Individuals
objects described by a set of data
Variables
Characteristics or measurements we are interested in studying
Quantitive Variables
variables that can be counted or measured
Data
Values of variables
Stratified Sampling
Dividing a population into distinct subgroups based on specific characteristics.
Strata
subgroups within a population that share a common characteristics.
, Proportionate Sample
a sample where the number of individuals selected from each stratum is proportional to the size of the
stratum population. (25% of the high school population is freshman, then 25% of the sample should be
freshman)
Cluster Sampling
Dividing the population into clusters, which are naturally occurring groups like schools, neighborhoods,
or cities.
Systematic Sampling
Selecting every 'nth" individual from a list of the population starting from a randomly chosen point. (List
of 1000 people if you want a sample of 100 the sampling interc=val would be every 10th person is
selected)
Observational Study
Observe and record data without intervention
Sample Survey
Ask individuals to self-report the values of variables.
experiment
Manipulate variables and observe their effects.
Explanatory Variable
Variable believed to cause the change
Response variable
Variable effected
Treatments
Different values of the explanatory variable
Experimental Unit
Single object or individual being measured
Replication
Repeating the experiment with a sufficiently large sample size or reproducing the entire study to
confirm previous findings
Control Group
Group of participants in an experiment who do not receive the experimental treatment.
Blidning
