Tags & Description
Statistics
science of analyzing and gathering data
individual data
people or things that are being studied
Variable data
characteristics or values being studied
What are ways to gather data
by counting, measuring, asking questions, surveys, or general observations
Examples of variables
Major, Grade, Points
Examples of individuals
Names of ppl surveyed
categorical variable
labels or descriptions ex: major or grades
numerical variable
numerical measurements ex: points
How do you summarize categorical variables?
By using a proportion percent
How do you summarize numerical variables
by using the mean/average
continuous variables
variables that can take on any value in a given data set
discrete variables
variables that can only take on a particular value in a data set
Which describes a discrete variable
a
Which describes a continuous variable
b
Population
All individuals as a group
Sample
smaller group of individuals; a subset of a population
census
getting data from every individual in a population
Parameter
numeric summary that comes from population population --> parameter
Statistic
numeric summary that comes from a sample sample--> statistic
Types of Samples
Representative sample, Random sample, Convenience sample
Representative sample
same relevant characteristics as population, not favorable of one group over another
random sample
a sample in which every element in the population has an equal chance of being selected
a random sample is a form of a representative sample
convenience sample
sample where individuals are chosen because they are easy to observe
biased statistical study
design or execution that will favor certain outcomes over others
selection bias
sample method chosen leads to unrepresentable samples of population
What are the two types of statistical studies?
Observational studies and experiments
Observational study
observing or surveying individuals
Experiment
an attempt to influence or change individuals
Subjects
individuals or things we are receiving data from
Explanatory variable (Treatment)
(Independent) variable in the experiment that researchers change, affect, or influence
Response Variable
(Dependent) variable in experiment that is expected to respond to the explanatory variable
Extraneous variables
Variables other than explanatory or response variables that may affect the outcome or response variable Ex: time, temperature, schedules, etc.
confounding variable
an extraneous variable that does affect the outcome of the experiment/response variable