### PowerPoint :: 01

```Stats Starts Here
• Statistics gets a bad rap, and
• Statistics courses are not necessarily
chosen as fun electives, but
• Statistics can be fun! Learning to think
clearly with data will open your eyes to
seeing the world more clearly…
Slide 1-1
What Is (Are?) Statistics?
• Statistics (the discipline) is a way of
reasoning, along with a collection of tools
and methods, designed to help us
understand the world.
• Statistics (plural) are particular
• Data are values along with a context.
Slide 1-2
• In a word, Statistics is about variation.
• When we make measurements, there is
variation out there that we cannot see, so
all measurements are imperfect.
• Statistics is thus a way for us to
understand the real, imperfect world in
which we live.
Slide 1-3
Think, Show, Tell
• There are three simple steps to doing Statistics
right: think, show, and tell:
– Think first. Know where you’re headed and why. It will
save you a lot of work.
– Show is what most people think Statistics is about.
While the mechanics of calculating statistics and
graphical displays are important, they are not the
most important part of Statistics.
– Tell what you’ve learned. Until you’ve explained your
results so that someone else can understand your
conclusions, the job is not done.
Slide 1-4
Statistics – What do students find hard?
• “Understood the material in class,
but found it hard to do the homework.”
• “Should be more like a math course,
with everything laid out beforehand.”
• “More problems in class should be like
the HW and tests …”
Slide 1-5
Easy Part /\ Hard Part
• The easy part
– Given the formula, turn the crank ...
• The hard part
– Putting it all together
» Real world
» Experience
» Methods
Slide 1-6
Example …
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Wed 6/22/2011 5:58 PM
Dr. Robinson,
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Wed 6/22/2011 6:15 PM
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Never mind
I got it!
I can’t figure out the problems of 9.1 numbers 17 and 19.
How do I determine the lower and upper bounds?
This is so frustrating
Thank you
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Slide 1-7
So What Do We Know?
• Statistics can be (and is) fun!
• Statistics gives us a way to work with the
variability in the world around us.
• We are embarking on an exciting journey
of learning Statistics…
Slide 1-8
WHAT IS STATISTICS?
Statistics is a group of methods used to
collect, analyze, present, and interpret
data and to make decisions.
9
Descriptive Statistics consists of methods for
organizing, displaying, and describing data by
using tables, graphs, and summary measures.
Inferential Statistics consists of methods that use
sample results to help make decisions or
10
A population consists of all elements –
individuals, items, or objects – whose
characteristics are being studied.
A portion/subset of the population selected
for study is referred to as a sample.
11
A variable is a characteristic under study
that assumes different values for different
elements, units, subjects, individuals.
An experimental unit is the object
(element, unit, subject, individual)
upon which we collect data.
12
• Quantitative Data – numerical scale
• Qualitative Data – categories
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Variable
Quantitative
Discrete (e.g.,
number of
houses, cars,
accidents)
Continuous
(e.g., length,
age, height,
weight, time)
Qualitative or
categorical (e.g.,
make of a computer,
hair color, gender)
14
From Where Does Data Come … ??
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Published Source
Designed Experiment
Survey
Observational Study
15
```