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Statistics:
Everywhere
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Chris Jordan Silent Spring, 2014 44x58" and 60x80"; made from
28 graphite drawings by Rebecca Clark
Depicts 183,000 birds, equal to the estimated number of birds that die in
the United States every day from exposure to agricultural pesticides.
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Building Blocks, 2013 14x20 feet, in 70 2x2-foot panels
Depicts 1.2 million children’s building blocks, equal to the number of students who
drop out of high school every year in the U.S. This averages about 7000 students
per school day. Chris Jordan
Running the Numbers: An American Self-Portrait(2006 - Current)
Running the Numbers looks at contemporary American culture through the
austere lens of statistics. Each image portrays a specific quantity of
something: fifteen million sheets of office paper (five minutes of paper use);
106,000 aluminum cans (thirty seconds of can consumption) and so on. My
hope is that images representing these quantities might have a different
effect than the raw numbers alone, such as we find daily in articles and
books. Statistics can feel abstract and anesthetizing, making it difficult to
connect with and make meaning of 3.6 million SUV sales in one year, for
example, or 2.3 million Americans in prison, or 32,000 breast augmentation
surgeries in the U.S. every month. This project visually examines these vast
and bizarre measures of our society, in large intricately detailed prints
assembled from thousands of smaller photographs. Employing themes such
as the near versus the far, and the one versus the many, I hope to raise
some questions about the roles and responsibilities we each play as
individuals in a collective that is increasingly enormous, incomprehensible,
and overwhelming.
~cj, Seattle, 2008
For more on Chris Jordan go to Ted Talks
http://www.ted.com/talks/chris_jordan_pictures_some_shocking_stats?langu
age=en
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More at Gapminder.com
WHY? WHY? WHY? MORE STATISTICS
Enough
Stats!
I want to
help
people –
I want to study
people, not
Means,
Standard
Deviations and
t-tests
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Focus of the class
• Knowing which
statistics to use to
answer questions
• Interpreting the
statistical output (i.e.,
answer) and
communicating
findings.
Success in Statistics
• Keep focus on
concepts (not
memorization but
understanding)
• Be sure to understand
each concept before
going to the next.
(Statistics is
cumulative)
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Your responsibility
• Keep up (practice,
homework, office
hours, academic
center)
• Help each other!
Definition
• Statistics: set of methods and rules for organizing, summarizing, and interpreting information.
• Provide researchers with a set of standardized techniques that are recognized and understood throughout the scientific community.
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Research Process: The Role of Statistics
1. Research Question
Describing Behavior, predicting behavior, explaining/understanding behavior and changing
behavior
2 Conduct the Study.
Hypothesis
Measure Variables
Identify a Sample
Select a Research Strategy
(experimental or correlational)
6. Refine or Reformulate your Research Idea
Use the key results to modify, refine, or expand your
original idea or to generate new ideas.
3. Conduct the Study
Collect the data
4. Evaluate the Data
Use the appropriate descriptive
and inferential statistics to
summarize and interpret the
results
5. Report the Results
Use the established guidelines for
format and style to prepare an
accurate and honest report that
also protects the anonymity and
confidentiality of the participants
(Based on Gravetter & Forzano, 2003)
There are three kinds of lies:
lies, damned lies and statistics
Disraeli (British politician and
author, 1804-1881)
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THE SAMPLE
All individuals of interest
THE POPULATION
The sample is
selected from
the population
The results
from the sample
are generalized
to population
The individuals selected
to participate in the research study
THE SAMPLE THE POPULATION
Parameter
A numerical value
that describes a
population
Definitions
Statistic
A numerical value
that describes a
sample
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Definition
• Variable is a characteristic or condition
that changes or has different values for
different individuals.
• Height, weight, gender, personality,
temperature, time of day, love, hate, voting
behavior etc.,
Independent & Dependent
Variables
Independent Dependent
Predictor/
Measured
Measured on
all participants
Manipulated
(levels,
conditions,
groups,
treatment
groups)
Subject
Quasi-Independent
Variable
Individual Difference
Variable
(age, gender, socio-
economic status)
Experimental
Design Quasi-
Experimental
Design
behavior/outcome
Measured to assess
changes
Measured on all
participants
Correlational
Design
correlational
Predictor
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Correlate the
two variables
Measure of
Recent Life
Stress
Measure Blood
Pressure
Participants
Research Design
Correlational Design: Stress and Health:
ss Blood pressure Life stress
1
2
3
4
5
6
7
8
160 / 110
150 / 120
160 / 110
180 / 130
180 / 130
170 / 120
150 / 120
170 / 120
25
30
25
15
20
22
23
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MANIPULATION
GROUP
Stress Group
CONTROL
No- Stress
Group
Give a speech on
statistics
Blood pressure
measured (DV)
Sit quietly
Blood pressure
measured (DV)
Experimental Design
Manipulated Independent
variable
Random
Assignment
Stress Group No-Stress
Group
160 / 110
150 / 120
160 / 110
180 / 130
160 / 110
150 / 120
160 / 110
180 / 130
180 / 130
170 / 120
150 / 120
170 / 120
160 / 110
150 / 120
160 / 110
180 / 130
Compare
scores
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Compare the blood
pressure of males and
females
Measure Blood
Pressure
Measure Blood
Pressure Males
Research Design: Quasi-Experimental Design or Natural Groups
Design (no manipulation) ---Gender and Health
Females
Subject Variable
NO
Random
Assignment
Males Females
160 / 110
150 / 120
160 / 110
180 / 130
160 / 110
150 / 120
160 / 110
180 / 130
180 / 130
170 / 120
150 / 120
170 / 120
160 / 110
150 / 120
160 / 110
180 / 130
Problems that can arise in experiments
(Extraneous/Confounding variable
Lecture only Lecture with lab
Professor Smith Professor Jones
Low
final exam
scores
High
final exam
scores
Independent Variable
Confounding Variable
Dependent Variable
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p. 154
Definitions
• Data (plural): measurements or
observations.
• data set collection of measurements or
observations.
• A datum (singular): single measurement
or observation; commonly called a score
or raw score.
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Four Levels of Measurements
• Nominal
– Numbers stand for names and do not have any quantitative value
– Measures categories/classifications
– Used to identify, label and categorize things
– Interest in measuring different types or kinds
A scale that categorizes items
Four Levels of Measurement
• Nominal
– Assign a number to groups- the number has no
meaning.
Gender: Female = 1 or Female = 2 Male = 2 or Male = 1
1=“think of love as an addiction”
2=“think of love as a business”
3=“think of love as a game”
4=“think of love as lust” (Sternberg, 1994)
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Four Levels of Measurement
• Ordinal Numbers: A scale that categorizes and rank orders items
• Bigger means More
– Numbers stand for different things, but the scale also give information about order
– People with higher scores have more of a given quality
– Rank order (first, second, third)- preferences
– Says nothing about the difference among items/numbers
Four Levels of Measurement
• Bigger Means More
3= pop music
2= hard rock
1= classical
• Rank ordering of
distressed couples
The Smiths: 5= most
distressed
The Bonds: 4= very
distressed
The Carrs: 3= moderately
distressed
The Burns: 2= distressed
The Teers: 1= a little
distressed
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Four Levels of Measurement • Interval: A scale that categorizes and rank
orders items, and has equal intervals
Know how much more
– Equal distance between any two consecutive
measures
– The difference is meaningful Scores on a Relationship satisfaction scale
10 100
Extremely Extremely
Unhappy Happy
Four Levels of Measurement • Ratio: A scale that categorizes and rank orders
items, has equal intervals, and a zero that means the absence or none of the thing being measured
• Absolute Zero – Intervals + meaningful zeros
– 0 is meaningful point = nothing absence of the variable
– Can make ratio statements
– Rarely used in psychology
– (age, reaction time, number of errors on a test, height, weight)
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Discrete vs. Continuous Variables
• Discrete Variables: consists of separate categories. All values are whole numbers.
• Continuous Variables: Variable that is not measured on distinct categories. Values can fall anywhere on a scale. – Continuous variables are defined by the real limits
– A real limit is defined as +/- .5 of the observed highest score.
Continuous Variables: Real Limits
weight
148 150 151 152
149.5
Lower
real
limit
150.5
Upper
real
limit
149
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Rounding
• Rounding
– 4.366 = 4.37
– 4.764 = 4.76
– 4.365 = 4.37
– 4.345 = 4.34
6 > 5
4 < 5
The number before the
5 determines the value