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2

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

28

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