Sta220
Section 1.1, 1.2, 1.3
Lesson Objective #1: Define statistics and statistical thinking
Statistics:
Statistics is the science of _______________, _______________, _______________, and
_______________ information to draw _____________ or _____________
_____________. In addition, statistics is about providing a measure of _____________
in any conclusions.
Data:
Data describe __________________ of an individual.
Data are used to draw a conclusion or make a decision.
One goal of statistics is to describe and understand sources of __________________.
Lesson Objective # 2: Explain the Types of Statistics Applications
Statistic and Parameter:
__________________ statistics consist of organizing and summarizing data. Descriptive
statistics describe data through numerical summaries, tables, and graphs. A
_________________ is a numerical summary based on a sample.
_________________ statistics uses methods that take results from a sample, extends
them to the population, and measures the reliability of the result. A _______________ is
a numerical summary of a population.
Lesson Objective # 3: Fundamental Elements of Statistics
Statistical methods are particularly useful for studying, analyzing, and learning about
_____________ of _______________________.
An __________________________________ is an object ( e.g., person, thing,
transaction, or event) about which we collect data.
Population and Sample:
The ____________ group of individuals to be studied is called the population. An
______________ is a person or object that is a member of the population being studied.
A _____________ is a subset of the population that is being studied.
The _______________ is a characteristic or property of an individual experimental (or
observational) unit in the population.
Example: ______________ is a variable
Male, female, and so on are __________
A statistical inference is an _______________, ______________, or
__________________ about a ___________________ based on information
_________________ in a _______________.
A ____________________________is a statement (usually quantitative) about the
degree of uncertainty associated with a statistical inference.
The Process of Statistics:
1. _______________________
2. _______________________
3. _______________________
4. _______________________
EXAMPLE
Illustrating the Process of Statistics
Many studies evaluate batterer treatment programs, but there are few experiments
designed to compare batterer treatment programs to non-therapeutic treatments, such as
community service. Researchers designed an experiment in which 376 male criminal
court defendants who were accused of assaulting their intimate female partners were
randomly assigned into either a treatment group or a control group. The subjects in the
treatment group entered a 40-hour batterer treatment program while the subjects in the
control group received 40 hours of community service. After 6 months, it was reported
that 21% of the males in the control group had further battering incidents, while 10% of
the males in the treatment group had further battering incidents. The researchers
concluded that the treatment was effective in reducing repeat battering offenses.
(Source: The Effects of a Group Batterer Treatment Program: A Randomized
Experiment in Brooklyn by Bruce G. Taylor, et. al. Justice Quarterly, Vol. 18, No. 1,
March 2001.)
Step 1: Identify the research objective.
Step 2: Collect the information needed to answer the question.
Step 3: Organize and summarize the information.
Step 4: Draw conclusions from the data.
Example 1
According to Variety (Aug. 27, 2009), the average age of viewers of live television
programs broadcast on CBS, NBC, and ABC is 51 years. Suppose a rival network (e.g.
Fox) executive hypothesizes that the average age of Fox viewers is less than 51. To test
her hypotheses, she samples 200 Fox viewers and determines the age of each.
a. Describe the population.
b. Describe the variable of interest.
c. Describe the sample.
d. Describe the inference.
Example 2
“Cola Wars” is the popular term for intense competition between Coca-Cola and Pepsi
displayed in their marketing campaigns, which have featured movie and television stars,
rock videos, athletic endorsements, and claims of consumer preference based on taste
tests. Suppose, as part of a Pepsi marketing campaign, 1,000 cola consumers are given a
blind taste test (i.e., a taste test in which the two brand names are disguised). Each
consumer is asked to state a preference for Brand A or brand B.
a. Describe the population.
b. Describe the variable of interest.
c. Describe the sample.
d. Describe the inference.