Psychology 101
Ticket # 32121
M-218
Melissa Ferguson, PhD
T/Th 7:30-8:45
Required Text: Invitation to Psychology 4th ed.
Wade & Tavris (2008)
ISBN: 9780131750630
• Viking Bookstore
– (562) 938-4225 ext. 2462
– Hours: 7:30 am – 7 pm M-Th
7:30 am – 2:30 pm Fri,
closed Sa/Su
– Online
Psych 101
Melissa Ferguson
• Email: mferguson@lbcc.edu
• Office:
• Office Hours: after class and by appt
Melissa Ferguson, PhD
• BA Psychology – SDSU
– Developmental Psych Research
• MA Psychology – SDSU
– Physiological Psych Research
• PhD Neuroscience – USC
– Aging & Plasticity in the brain
• Postdoc Biochemistry – USC
– Aging
Psych 101
Course Description
• Survey course on:
– Science of Psychology
• Development, Learning, Memory, Thinking,
Motivation, Emotion, Perception, Abnormal
Psychology, Biology of Behavior
– Critical & Scientific Thinking
– Gender, Ethnic, & Cultural Differences
• You will be tested on:
• Text, lectures, class discussions, assignments,
group activities and other multimedia
supplements
Tests
• 3 mid-term exams
– Multiple choice
– You will need to THINK CRITICALLY
– Active review session if time permits
• FINAL EXAM
– Cumulative
– OPTIONAL
• NO MAKEUP EXAMS!!!
Quizzes and Assignments
• Quizzes:
– 3 reading quizzes  1 per section
– 10 questions = 10 points
= 30 points toward total grade
– Will be announced IN CLASS
– Combination MC, T/F, fill in blank, & short answer
• Assignments:
– 3 writing assignments = 25 points each
= 75 points toward final grade
Attendance Points
• Attendance Points:
 2 points/day starting Jan 26= 50 points total
 If you are late or leave early, you risk getting
only half the points for that day
 Can raise (or lower) your grade!
 Perfect attendance = 5 extra points!
Extra Credit
• Not a requirement
• Not guaranteed to raise your grade
• Opportunities throughout the semester
FINAL GRADE CALCULATION
NO CURVE
90-100% of total possible points = A
80-89% of total possible points = B
70-79% of total possible points = C
60-69% of total possible points = D
Below 60% of total possible points = F
Tests = 3 Exam Scores (x 100 points each)
Assignments (3 x 10 points each)
Quizzes (3 x 10 points each)
Attendance Points
Total
= 300 points
= 75 points
= 30 points
= 50 points
= 455 points
Miscellaneous
• Questions
– Please feel free to ask questions throughout the
class as I want to encourage discussions
What is Psychology?
Learning Objectives:
1. Why is psychology a science, and how can it be distinguished
from pseudoscience and folk wisdom?
2. How did psychology come to be a science, i.e. what is its
history?
3. Understand the focus of the major perspectives, and how each
explains and understands thoughts feelings and behavior.
4. How do the potential jobs in psychology differ from one another
in their training, and background?
5. Be able to distinguish between psychotherapists, psychiatrists,
and psychoanalysts
What is Psychology
• How do you know that George Washington was the first
President of the United States?
– Authority
• We trust the authority of historians and history books
• How do you know you really have a stomach?
• What makes you so sure the sun will rise tomorrow?
– Reason
• Deductive reasoning
• Inductive reasoning
• Are you sure you don’t have a big hole in the back of your
pants?
• How do you know the color of the shirt I am wearing?
– Observation
chapter 1
What is psychology?
Psychology is Empirical
• It relies on evidence gathered by careful
observation, experimentation, or
measurement
Definition:
The discipline concerned with behavior
and mental processes and how they are
affected by an organism’s physical state,
mental state, and external environment.
chapter 1
What Psychology is NOT…
Psychobabble
 Self-help books
 Talk shows
Pseudoscience
 Handwriting analysis
 Astrology
Common Sense
 Your baby will be smarter if he/she listens to
classical music
 Abused children will become abusive parents
chapter 1
Psychology’s past
• Phrenology
– Bumps on the skull, are thought to related to the size of the
underlying ‘organs’ in the brain and account for specific
character and personality traits
• Wilhelm Wundt (1832-1920)
– 1879 established first psychological laboratory
– Trained introspection
» Self- observation and description
chapter 1
Psychology’s past
• Functionalism
– Emphasized function or purpose of behavior - how and why
– William James (1842-1910)
– broadened field of psychology to include the study of
children, animals, religious experiences, and stream of
consciousness
• Psychoanalysis
– Sigmund Freud (1856-1939)
– Belief that physical symptoms have mental causes,
resulting from internal conflict and emotional trauma that
was not resolved during ones childhood.
For next class
1. Get textbook!
2. Read Ch 1 – at least through Critical
Thinking Guidelines
Last Class in Review
• What is Psychology?
• A science that relies on empirical evidence gathered by
observation, experimentation or measurement
• It examines behavior and mental processes and how
they are affected by the physical and mental state, as
well as the external environment
• It is NOT psychobabble, a pseudoscience or simply
common sense
• What are the foundations of modern
psychology, i.e. psychology’s past?
–
–
–
–
Phrenology – bumps on skull relate to character
Wilhelm Wundt – first psychological lab, observation
Functionalism – how and why of behavior
Psychoanalysis – unconscious mind controls behavior
» FREUD
What is Psychology?
Major Perspectives and Jobs
• Learning Objectives:
– Understand the focus of the major perspectives, and how
each explains and understands thoughts feelings and
behavior.
– How do the potential jobs in psychology differ from one
another in their training, and background?
– Be able to distinguish between psychotherapists,
psychiatrists, and psychoanalysts.
– What are the 8 critical thinking guidelines that help in
understanding psychological issues?
chapter 1
Major Psychological
perspectives
1.
Biological perspective
2.
Learning perspective
3.
Cognitive perspective
4.
Sociocultural perspective
5.
Psychodynamic perspective
Albert Einstein
chapter 1
The biological
perspective
Psychological approach that focuses
on how genes, hormones, brain
function, and other biological factors
affect behavior, feelings, perceptions,
and thoughts
chapter 1
The learning
perspective
Emphasizes how the environment
and experience affect a person’s
or animal’s actions
• Behaviorists
• Focus on environmental rewards and
punishers
• Observation is key
•Social-Cognitive
• Combines behavioralism with research on
thoughts, values, and intentions
• Environment, imitation, and internal
thoughts influences behavior
chapter 1
The cognitive
perspective
Psychological approach that
emphasizes what goes on in people’s
heads
• Examines internal mental processes
•
•
•
•
•
•
Creativity
Perception
Thinking
Problem Solving
Memory
Language
chapter 1
The sociocultural
perspective
Psychological approach that
emphasizes social and cultural
forces outside the individual
• Addresses ethnicity, gender, culture, and socioeconomic status and how people’s behavior and
outlook differ because of these factors.
chapter 1
The psychodynamic
perspective
Psychological approach that
emphasizes unconscious dynamics
within the individual, such as inner
forces, conflicts, or the movement
of instinctual energy
• Unconscious thoughts, desires, and conflicts
• Outgrowth from Freud
chapter 1
Humanist psychology
Psychological approach that
emphasizes personal growth and
the achievement of human
potential, rather than the scientific
understanding of behavior
• Free will, personal growth, resilience,
achievement of human potential and selffulfillment
What can you do with a
background in Psychology?
1. Teaching and research at colleges and universities
2. Psychological practice
3. Research or application of psychology in non-academic
settings
chapter 1
Psychological research
Research in areas of basic or
applied psychology
•
•
•
•
•
•
•
Experimental psychologists
Physiological psychologists
Developmental psychologists
Social psychologists
Educational psychologists
Industrial/organizational psychologists
Psychometric psychologists
chapter 1
Psychological practice
• Counseling psychologists
• help people deal with problems associated with
everyday life
• School psychologists
• work to enhance student performance and provide
a supportive learning environment
• Clinical psychologists
• diagnose, treat, and study mental or emotional
problems.
• PhD, PsyD or EdD
• Psychiatrists
• diagnose, treat, and study mental or emotional
problems
• have an MD
chapter 1
Psychologists in other
settings
Sports
Consumer issues
Advertising
Organizational problems
Environmental issues
Public policy
Opinion polls
Military training
Animal behavior
Legal issues
chapter 1
Critical thinking
guidelines
1. Ask Questions
2. Define you terms
3. Examine the evidence
4. Analyze Assumptions and Biases
5. Avoid emotional reasoning
6. Don’t oversimplify
7. Consider other interpretations
8. Tolerate uncertainty
For Next Class
• Finish reading Ch 1
Last class in review
• 5 Psychological Perspectives
–
–
–
–
Biological – genes, hormones, brain function
Learning – environment and experience
Cognitive – what is in people’s heads
Sociocultural – ethnicity, gender, culture, and socioeconomic
status
– Psychodynamic – unconsciousness
– Plus Humanism – self- fulfillment and –achievement
• Jobs in Psychology
– Research – basic & applied
– Practice – counseling, school psych, clinical
– Other settings
• Critical Thinking Guidelines
Critical Thinking Guidelines
and Research Methods
• Learning Objectives:
– What are the 8 critical thinking guidelines that help in
understanding psychological issues?
– What are the defining elements of descriptive research?
Can you give an example of a case study, observational
study, a psychological test, and a survey?
– What are positive and negative correlations and what do
they look like?
Group Exercise
• Work in groups of 3-4
• Identify the critical thinking guidelines that
were violated in the stories presented on the
handout
Methods used to gather
empirical evidence
• Descriptive Studies
• Correlations
• Experiments
chapter 1
Descriptive methods
Methods that yield descriptions of
behavior, but not necessarily causal
explanations
•
•
•
•
Case Studies
Observational Studies
Tests
Surveys
chapter 1
Case studies
A detailed description of a
particular individual being
studied or treated, which may be
used to formulate broader
research hypotheses
•Most commonly used by clinicians
•Occasionally used by researchers
Observational studies
Researchers carefully and
systematically observe and record
behavior without interfering with
behavior
• Naturalistic observation
• Natural environments
• Laboratory observation
• Controlled setting
Psychological tests
Procedures used to measure and
evaluate personality traits,
emotional states, aptitudes,
interests, abilities, and values
• Objective - inventories
• Projective – ambiguous stimuli
Rorschach Inkblot Test
Psychological tests cont.
• Characteristics of a good test
include:
• Standardization
• Reliability
• Validity
– content & criterion
Surveys
Questionnaires and interviews that ask
people about experiences, attitudes, or
opinions
• Representative sample
Group of subjects, selected from the population for
study, which matches the population on important
characteristics such as age and sex
• Volunteer Bias
Correlational study
A descriptive study that looks for a
consistent relationship between two
phenomena
•Correlation
• A statistical measure of how strongly
two variables are related to one another
• Correlational coefficients can range from
0.0 – 1.0
• negative or positive
Direction of correlations
Positive
correlations
An association between
increases in one variable
and increases in another, or
decreases in one variable
and decreases in the other.
Negative
correlations
An association between
increases in one
variable and decreases
in another.
Scatterplots
Correlations can be represented by
scatterplots.
Your turn
What kind of
correlation is
this?
1. Positive
2. Negative
3. No correlation
Your turn
What kind of
correlation is
this?
1. Positive
2. Negative
3. No correlation
Correlations do NOT prove Cause and Effect!
• It is very important to remember that just because 2
variables are correlated, that doesn’t mean that 1
causes the other
• X and Y are positively correlated
– X causes Y
– Y causes X
– X and Y can be the result of variable Z
Causal and Non-causal language
• Sexual lyrics prompt teens to have sex
• Listening to sexual lyrics associated with teen sex
• Memory retention enhanced by sleep
• People who sleep more, remember more!
• Kids who take music lessons have bigger brains
• Music lessons improve kids' brain development
Causal and Non-causal language
• Sexual lyrics prompt teens to have sex
• Listening to sexual lyrics associated with teen sex
• Memory retention enhanced by sleep
• People who sleep more, remember more!
• Kids who take music lessons have bigger brains
• Music lessons improve kids' brain development
Causal and Non-causal language
• Sexual lyrics prompt teens to have sex
• Listening to sexual lyrics associated with teen sex
• Memory retention enhanced by sleep
• People who sleep more, remember more!
• Kids who take music lessons have bigger brains
• Music lessons improve kids' brain development
Causal and Non-causal language
• Sexual lyrics prompt teens to have sex
• Listening to sexual lyrics associated with teen sex
• Memory retention enhanced by sleep
• People who sleep more, remember more!
• Kids who take music lessons have bigger brains
• Music lessons improve kids' brain development
chapter 1
Experimental Method
A controlled test of a
hypothesis in which the
researcher manipulates one
variable to discover its effect
on another.
•Variables
•Control conditions
•Random assignment
•Statistics
Group Exercise:
Research Methods
• With your group match the appropriate research
method with its description
• We’ll discuss the answers as a class when all the
groups are done
Last Class in Review
• 8 Critical Thinking Guidelines
–
–
–
–
–
–
–
Ask questions
Define your terms
Examine the evidence
Analyze assumptions and biases
Don’t over-simplify
Consider other interpretations
Tolerate uncertainty
• Psychological Methods
– Descriptive
» case studies, observational studies, psych tests, surveys
– Correlational
» Positive or Negative
» Do not prove cause and effect!
Research Methods – Experimental
Methods & Statistics
• What is the difference between and independent variable and
dependent variable?
• What is the difference between an experimental and control
group?
• What is the difference between random selection and random
assignment? Why do researchers use random selection and
random assignment?
• What is the difference between a single-blind and double blind
experiment?
• Why would someone use descriptive vs inferential statistics?
chapter 1
Experimental Method
A controlled test of a
hypothesis in which the
researcher manipulates one
variable to discover its effect
on another.
•Variables
•Control conditions
•Random assignment
•Statistics
chapter 1
Experimental Method:
Variables of interest
Independent
variables
Variables the
experimenter
manipulates
Dependent
variables
Variables the
experimenter predicts
will be affected by
manipulations of the
independent
variable(s)
chapter 1
Your turn
An experimenter wants to study the effects of
music on studying. He has some students
study while listening to music and others study
in silence, and then compares their test scores.
What is the independent variable in this
experiment?
1.
2.
3.
4.
The
The
The
The
students
presence of music while studying
kind of music
test scores
chapter 1
Your turn
An experimenter wants to study the effects of
music on studying. He has some students
study while listening to music and others study
in silence, and then compares their test scores.
What is the independent variable in this
experiment?
1.
2.
3.
4.
The students
The presence of music while studying
The kind of music
The test scores
chapter 1
Control conditions
A comparison condition in which
subjects are not exposed to the
same treatment as in the
experimental condition
Experimental & Control Conditons
chapter 1
Random assignment
Each individual participating in the study has
the same probability as any other of being
assigned to a given group.
chapter 1
Experimenter effects
Unintended changes in
subjects’ behavior due
to cues inadvertently
given by the
experimenter.
Strategies for
preventing
experimenter effects
include single- and
double-blind studies.
chapter 1
Descriptive statistics
Statistical procedures
that organize and
summarize research
data
• Examples
•Arithmetic mean
•Standard deviation
chapter 1
Descriptive statistics
Scores on a test
99
92
Mean
86
867 / 10 = 86.7
88
70
91
Standard Deviation
77
8.1
85
89
1
0
90
65
70
75
80
85
90
95
100
chapter 1
Inferential statistics
Statistical procedures that allow
researchers to draw inferences about how
statistically meaningful a study’s results
are.
• Significance tests
•Significance means that the
possibility your results occurred by
chance is very small
120
*
Test scores
100
80
60
40
20
0
4
6
Hours of sleep
8
chapter 1
Statistics
Hypothesis:
Students who sleep less
than 4 hours before an
exam will perform more
poorly than those getting 8
hours or more.
sum
mean
std dev
Test Scores
4 hours
6 hours
8 hours
70
77
93
75
82
92
76
81
95
72
83
96
73
84
94
80
85
96
71
80
94
77
82
98
594
654
758
74.25
81.75
94.75
3.370036 2.492847 1.908627031
120
Test scores
100
80
60
40
20
0
4
6
Hours of sleep
8
chapter 1
Statistics
Hypothesis:
Students who sleep less
than 4 hours before an
exam will perform more
poorly than those getting 8
hours or more.
sum
mean
std dev
Test Scores
4 hours
6 hours
8 hours
70
77
93
75
82
92
76
81
95
72
83
96
73
84
94
80
85
96
71
80
94
77
82
98
594
654
758
74.25
81.75
94.75
3.370036 2.492847 1.908627031
120
*
Test scores
100
80
60
40
20
0
4
6
Hours of sleep
8
Random Selection vs. Random Assignment
• Random Selection:
– Every member of a given population has an equal chance of
being selected for the sample
– Background characteristics (variables) are similar in selected
sample and population
• e.g. age, gender or race
– External validity
• Random Assignment:
– Every member of the sample has an equal chance of being
placed in the the experimental or control groups
– Distributes variability (background characteristics) evenly
among groups
– Internal validity
How to Select a Simple Random Sample?
1. Define the population
– Head Start families in Los Angeles (100)
2. Determine desired sample size
– 25 families
3. List all members of population
– Sampling frame
Sampling Frame
Head Start Families in Los Angeles
Family Name1 Gender2 Age3
Agular
M
2
Aragon
F
3
Backman
M
2
Beattis
M
2
Bradshaw
M
3
Brinks
F
1
Bryant
M
1
Cabrera
F
2
Callaway
F
2
Carpenter
F
2
Casani
F
2
Chang
F
3
Chavis
F
3
Chen
F
2
Cho
M
1
Christiansen
M
3
Coleman
F
1
Conseco
M
2
Craig
M
2
Davis
M
3
Desimone
F
1
Desmet
F
2
Dolittle
M
1
Duggan
F
1
Dunham
M
1
Family Name1 Gender2 Age3
Dunniway
M
2
Elliott
M
1
Emal
F
1
Espinoza
F
1
Fernandez
M
1
Fisher
F
3
Gallegos
M
1
Garcia
M
1
Gomez
F
2
Gonzales
M
2
Gonzalez
M
3
Graham
F
1
Graziano
F
2
Grebe
M
1
Hernandez
M
3
Hill
M
1
Hokkyo
F
3
Holmes
M
2
Horn
M
1
Horne
F
1
Hykal
M
1
Jensen
F
1
Jiminez
F
3
Johnson
F
3
Johnston
M
2
Family Name1 Gender2 Age3
Jolly
F
1
Jones
M
2
Jose
M
2
Kim
F
3
Korenthal
F
2
Kung
F
1
Kuwata
F
2
Kwon
F
1
Lim
F
2
McAllister
F
1
McCallister
M
2
McGuire
M
3
McIntosh
F
3
Moore
F
1
Munoz
M
1
Nguyen
F
1
Nishi
F
3
Ortega
M
3
Parker
M
1
Porter
F
3
Pratt
F
2
Randazzo
F
1
Rebrin
F
3
Richards
M
3
Rodems
F
3
Family Name1 Gender2 Age3
Rodrieguz
M
3
Rothlisburger
M
3
Schindler
F
3
Sellers
M
3
Smith
M
1
Sosa
F
2
Sparks
M
3
Stevens
F
2
Stewart
M
1
Stuart
M
2
Terry
M
3
Thompson
M
3
Toroser
M
2
Trainor
F
3
Tyson
M
3
Velasco
F
2
VonSachs
M
2
Vullo
M
3
Wachler
M
2
Walker
M
3
Walton
F
2
Wang
F
3
Ward
M
1
Williams
F
2
Zorner
F
1
1 - Last name of families with 1 child enrolled in Head Start program and at least 1 younger child not enrolled
2 - Gender of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
3 - Age of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
How to Select a Simple Random Sample?
1. Define the population
– Head Start families in Los Angeles (100)
2. Determine desired sample size
– 25 families
3. List all members of population
– Sampling frame
4. Randomly select individuals from population
– Random number table, computer program, hat model, coin toss
– www.random.org
– Excel formula: =RAND()
Random Selection of Sample from Population Using Excel
Family Name1 Gender2 Age3
Agular
M
2
Aragon
F
3
Backman
M
2
Beattis
M
2
Bradshaw
M
3
Brinks
F
1
Bryant
M
1
Cabrera
F
2
Callaway
F
2
Carpenter
F
2
Casani
F
2
Chang
F
3
Chavis
F
3
Chen
F
2
Cho
M
1
Christiansen
M
3
Coleman
F
1
Conseco
M
2
Craig
M
2
Davis
M
3
Desimone
F
1
Desmet
F
2
Dolittle
M
1
Duggan
F
1
Dunham
M
1
Family Name1 Gender2 Age3
Dunniway
M
2
Elliott
M
1
Emal
F
1
Espinoza
F
1
Fernandez
M
1
Fisher
F
3
Gallegos
M
1
Garcia
M
1
Gomez
F
2
Gonzales
M
2
Gonzalez
M
3
Graham
F
1
Graziano
F
2
Grebe
M
1
Hernandez
M
3
Hill
M
1
Hokkyo
F
3
Holmes
M
2
Horn
M
1
Horne
F
1
Hykal
M
1
Jensen
F
1
Jiminez
F
3
Johnson
F
3
Johnston
M
2
Family Name1 Gender2 Age3
Jolly
F
1
Jones
M
2
Jose
M
2
Kim
F
3
Korenthal
F
2
Kung
F
1
Kuwata
F
2
Kwon
F
1
Lim
F
2
McAllister
F
1
McCallister
M
2
McGuire
M
3
McIntosh
F
3
Moore
F
1
Munoz
M
1
Nguyen
F
1
Nishi
F
3
Ortega
M
3
Parker
M
1
Porter
F
3
Pratt
F
2
Randazzo
F
1
Rebrin
F
3
Richards
M
3
Rodems
F
3
Family Name1 Gender2 Age3
Rodrieguz
M
3
Rothlisburger
M
3
Schindler
F
3
Sellers
M
3
Smith
M
1
Sosa
F
2
Sparks
M
3
Stevens
F
2
Stewart
M
1
Stuart
M
2
Terry
M
3
Thompson
M
3
Toroser
M
2
Trainor
F
3
Tyson
M
3
Velasco
F
2
VonSachs
M
2
Vullo
M
3
Wachler
M
2
Walker
M
3
Walton
F
2
Wang
F
3
Ward
M
1
Williams
F
2
Zorner
F
1
1 - Last name of families with 1 child enrolled in Head Start program and at least 1 younger child not enrolled
2 - Gender of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
3 - Age of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
Benefits of using Random Selection
Family Name Gender Age
Bradshaw
M
3
Casani
F
2
Cho
M
1
Christiansen
M
3
Coleman
F
1
Conseco
M
2
Craig
M
2
Desmet
F
2
Dolittle
M
1
Emal
F
1
Graham
F
1
Holmes
M
2
Jiminez
F
3
Jolly
F
1
Kuwata
F
2
Lim
F
2
Munoz
M
1
Ortega
M
3
Randazzo
F
1
Richards
M
3
Schindler
F
3
Smith
M
1
VonSachs
M
2
Vullo
M
3
Walker
M
3
Sample Statistics
Male
56 %
Female 44 %
Age:
1
36 %
2
32 %
3
32 %
Population Parameters
Male 50 %
Female 50 %
Age:
1
34 %
2
33 %
3
33 %
Sample generalizes to population = External Validity
What happens if we don’t use Random Selection?
Family Name1 Gender2 Age3
Brinks
F
1
Bryant
M
1
Cho
M
1
Coleman
F
1
Desimone
F
1
Dolittle
M
1
Duggan
F
1
Dunham
M
1
Elliott
M
1
Emal
F
1
Espinoza
F
1
Fernandez
M
1
Gallegos
M
1
Garcia
M
1
Graham
F
1
Grebe
M
1
Hill
M
1
Horn
M
1
Horne
F
1
Hykal
M
1
Jensen
F
1
Jolly
F
1
Kung
F
1
Kwon
F
1
McAllister
F
1
Family Name1 Gender2 Age3
Moore
F
1
Munoz
M
1
Nguyen
F
1
Parker
M
1
Randazzo
F
1
Smith
M
1
Stewart
M
1
Ward
M
1
Zorner
F
1
Dunniway
M
2
Gomez
F
2
Gonzales
M
2
Graziano
F
2
Holmes
M
2
Johnston
M
2
Fisher
F
3
Gonzalez
M
3
Hernandez
M
3
Hokkyo
F
3
Jiminez
F
3
Johnson
F
3
Agular
M
2
Backman
M
2
Beattis
M
2
Cabrera
F
2
Family Name1 Gender2 Age3
Callaway
F
2
Carpenter
F
2
Casani
F
2
Chen
F
2
Conseco
M
2
Craig
M
2
Desmet
F
2
Aragon
F
3
Bradshaw
M
3
Chang
F
3
Chavis
F
3
Christiansen
M
3
Davis
M
3
Lim
F
2
McCallister
M
2
Pratt
F
2
Kim
F
3
McGuire
M
3
McIntosh
F
3
Nishi
F
3
Ortega
M
3
Porter
F
3
Rebrin
F
3
Richards
M
3
Rodems
F
3
Family Name1 Gender2 Age3
Jones
M
2
Jose
M
2
Korenthal
F
2
Kuwata
F
2
Sosa
F
2
Stevens
F
2
Stuart
M
2
Toroser
M
2
Velasco
F
2
VonSachs
M
2
Wachler
M
2
Walton
F
2
Williams
F
2
Rodrieguz
M
3
Rothlisburger
M
3
Schindler
F
3
Sellers
M
3
Sparks
M
3
Terry
M
3
Thompson
M
3
Trainor
F
3
Tyson
M
3
Vullo
M
3
Walker
M
3
Wang
F
3
1 - Last name of families with 1 child enrolled in Head Start program and at least 1 younger child not enrolled
2 - Gender of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
3 - Age of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
What happens if we don’t use Random Selection?
Family Name1 Gender2 Age3
Brinks
F
1
Bryant
M
1
Cho
M
1
Coleman
F
1
Desimone
F
1
Dolittle
M
1
Duggan
F
1
Dunham
M
1
Elliott
M
1
Emal
F
1
Espinoza
F
1
Fernandez
M
1
Gallegos
M
1
Garcia
M
1
Graham
F
1
Grebe
M
1
Hill
M
1
Horn
M
1
Horne
F
1
Hykal
M
1
Jensen
F
1
Jolly
F
1
Kung
F
1
Kwon
F
1
McAllister
F
1
Family Name1 Gender2 Age3
Moore
F
1
Munoz
M
1
Nguyen
F
1
Parker
M
1
Randazzo
F
1
Smith
M
1
Stewart
M
1
Ward
M
1
Zorner
F
1
Dunniway
M
2
Gomez
F
2
Gonzales
M
2
Graziano
F
2
Holmes
M
2
Johnston
M
2
Fisher
F
3
Gonzalez
M
3
Hernandez
M
3
Hokkyo
F
3
Jiminez
F
3
Johnson
F
3
Agular
M
2
Backman
M
2
Beattis
M
2
Cabrera
F
2
Family Name1 Gender2 Age3
Callaway
F
2
Carpenter
F
2
Casani
F
2
Chen
F
2
Conseco
M
2
Craig
M
2
Desmet
F
2
Aragon
F
3
Bradshaw
M
3
Chang
F
3
Chavis
F
3
Christiansen
M
3
Davis
M
3
Lim
F
2
McCallister
M
2
Pratt
F
2
Kim
F
3
McGuire
M
3
McIntosh
F
3
Nishi
F
3
Ortega
M
3
Porter
F
3
Rebrin
F
3
Richards
M
3
Rodems
F
3
Family Name1 Gender2 Age3
Jones
M
2
Jose
M
2
Korenthal
F
2
Kuwata
F
2
Sosa
F
2
Stevens
F
2
Stuart
M
2
Toroser
M
2
Velasco
F
2
VonSachs
M
2
Wachler
M
2
Walton
F
2
Williams
F
2
Rodrieguz
M
3
Rothlisburger
M
3
Schindler
F
3
Sellers
M
3
Sparks
M
3
Terry
M
3
Thompson
M
3
Trainor
F
3
Tyson
M
3
Vullo
M
3
Walker
M
3
Wang
F
3
1 - Last name of families with 1 child enrolled in Head Start program and at least 1 younger child not enrolled
2 - Gender of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
3 - Age of youngest child (1-3 years of age) that is not enrolled in the Head Start Program
What happens if we don’t use Random Selection?
Sample Statistics
Male
48 %
Female 52 %
Age:
1
100 %
2
---3
----
Population Parameters
Male 50 %
Female 50 %
Age:
1
34 %
2
33 %
3
33 %
What happens if we don’t use Random Selection?
Sample Statistics
Male
48 %
Female 52 %
Age:
1
100 %
2
---3
----
Population Parameters
Male 50 %
Female 50 %
Age:
1
34 %
2
33 %
3
33 %
Sample is NOT representative of the population =
Difficult to generalize results to the population
Random Assignment
• Use of random number table, computer program, hat
model, or coin toss to assign individuals in a sample
to a control or experimental group
• Evenly distributes background variables among the
groups
• Allows for experimenters to make statements about
cause and effect
Primary Goal of Research!
Benefits of using Random Assignment
Family Name Gender Age random assignment
Bradshaw
M
3
2
Casani
F
2
2
Cho
M
1
1
Christiansen
M
3
2
Coleman
F
1
1
Conseco
M
2
1
Craig
M
2
1
Desmet
F
2
2
Dolittle
M
1
2
Emal
F
1
1
Graham
F
1
1
Holmes
M
2
2
Jiminez
F
3
2
Jolly
F
1
2
Kuwata
F
2
1
Lim
F
2
2
Munoz
M
1
1
Ortega
M
3
2
Randazzo
F
1
2
Richards
M
3
1
Schindler
F
3
2
Smith
M
1
2
VonSachs
M
2
2
Vullo
M
3
1
Walker
M
3
1
Group 1 Statistics
(Control)
Male
Female
Age:
1
2
3
36.4 %
63.5 %
45.4 %
27.3 %
27.3 %
Group 2 Statistics
(Experimental)
Male
50 %
Female 50 %
Age:
1
28.6 %
2
35.7 %
3
35.7 %
Groups are similar to each other
= Internal Validity
What if we don’t use Random Assignment?
Family Name Gender
Cho
M
Coleman
F
Dolittle
M
Emal
F
Graham
F
Jolly
F
Munoz
M
Randazzo
F
Smith
M
Casani
F
Conseco
M
Craig
M
Desmet
F
Holmes
M
Kuwata
F
Lim
F
VonSachs
M
Bradshaw
M
Christiansen
M
Jiminez
F
Ortega
M
Richards
M
Schindler
F
Vullo
M
Walker
M
Age
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
random assignment
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
Group 1 Statistics
(Control)
Male
Female
Age:
1
2
3
46.2 %
53.8 %
69.2 %
30.8 %
---
Group 2 Statistics
(Experimental)
Male
67.7 %
Female 33.3 %
Age:
1
--2
33.3 %
3
66.7 %
What if we don’t use Random Assignment?
Family Name Gender
Cho
M
Coleman
F
Dolittle
M
Emal
F
Graham
F
Jolly
F
Munoz
M
Randazzo
F
Smith
M
Casani
F
Conseco
M
Craig
M
Desmet
F
Holmes
M
Kuwata
F
Lim
F
VonSachs
M
Bradshaw
M
Christiansen
M
Jiminez
F
Ortega
M
Richards
M
Schindler
F
Vullo
M
Walker
M
Age
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
random assignment
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
Group 1 Statistics
(Control)
Male
Female
Age:
1
2
3
46.2 %
53.8 %
69.2 %
30.8 %
---
Groups are NOT similar
= difficult to determine causality
Group 2 Statistics
(Experimental)
Male
67.7 %
Female 33.3 %
Age:
1
--2
33.3 %
3
66.7 %
Head Start Families
N = 100
Random Selection
External
Validity
Representative Sample
N = 25
Random Assignment
Internal
Validity
Control Group
Experimental Group
N =12
N = 13
Hypothesis
Early literacy intervention will improve emergent literacy in low-income children
Head Start Population
Random selection
Sample – 25 families
Random assignment
Control Group
No literacy intervention
Experimental Group
Independent variable
Test of language comprehension
and cognition before and after
intervention
Language & cognition scores
Early literacy intervention
Test of language comprehension
and cognition before and after
intervention
Dependent variable
statistics
Language & cognition scores
Writing Assignment 1
• Due 2/9
For NEXT WEEK
• READ CHAPTER 4!!
• Lots of definitions and new terms
Group Exercise
• What you’ll need:
• Deck of cards
• Coin or dice
• Background:
• Deck of cards = random sample
• Cards = participants/individuals
• Card have unique characteristics = background variables
– e.g. 26 black and 26 red; 13 each hearts, spades, clubs and diamonds
• Goal
• Each group will be given instructions on what to do with their deck of
cards, give me your results before you leave class and I’ll show you
everyone’s results next class
• This is to help you get a better understanding of how important random
assignment is