Transcript Week 2 lecture notes

Foundations of
Research
Introductory lectures 2: The Role and Structure of Science
 What does science
do?
 The core features of
a research study.
 Overall Research
approaches.
© Dr. David J. McKirnan, 2015
The University of Illinois Chicago
[email protected]
Do not use or reproduce without
permission
1
Foundations of
Research
Introductory lectures 2: The Role and Structure of Science

 What does
science do?

The core features of a
research study.

Overall Research approaches.
2
Foundations of
Research
What does science do?
Section Overview
What does Science do?
1. Describe the world
2. Made predictions (hypotheses)
3. Develop & test theories
4. Apply findings or theories
3
Foundations of
Research
1. Describing the world
1. Qualitative Description
 Simple observation: what goes on “in
the wild”.
 Anthropology, sociology, ethnography,
ethology….
 Many quantitative studies begin with
qualitative observations.
 Typically structured:
 field notes,
 checklists,
 behavioral counts...
4
Foundations of
Research
Describing the world
1. Qualitative Description
 Focus groups, structured observations…
… valuable for formulating hypotheses.
1.
2.
3.
4.
Description5
Prediction
Theory
Application
Foundations of
Research
Science and description
1.
2.
3.
4.
Description6
Prediction
Theory
Application
 Description … key
building block in all
areas…
World Music: A Retrospect Across The Globe, Venus Umesh. Link.
Mathematics Describing the Real World: Pre-calculus and
Trigonometry. Bruce H. Edwards, link here.
Foundations of
Research
1.
2.
3.
4.
Describing the world
Description7
Prediction
Theory
Application
2. Quantitative Description
 Tracking behavior or systems using numbers
 Surveys, polls…
 Archival data - uniform
crime reports.
 Physical observations
 Useful for both developing
and testing hypotheses.
From: Climate Site; How do climate models work? Link.
Examples of Descriptive Research
Foundations of
Research

1.
2.
3.
4.
Taxonomies: Classification systems
 Paleontology; shared v. distinct evolutionary
characteristics
 Psychology, Psychiatry; behavioral patterns or disorders.
 Demographics: ethnicity, socio-economic status,
language group…
Description8
Prediction
Theory
Application
Foundations of
Research

Taxonomies: Classification systems
 Look on the web site  find out your personality ‘type’.
1.
2.
3.
4.
Description9
Prediction
Theory
Application
Foundations of
Research

Examples of Descriptive Research
1.
2.
3.
4.
Description10
Prediction
Theory
Application
Epidemiology; Disease / behavior patterns in a
population.
 Where is AIDS most
common in the U.S.?
 Distribution of gun
assaults, by state.
 Methods:
 Direct measurement (e.g.,
surveys, disease reporting)
 Standard records (e.g., medical
visits & diagnoses)
http://filipspagnoli.wordpress.com/2011/11/17/human-rights-maps160-gun-crime-in-the-u-s-in-2010/
 Archival data (e.g., auto
accident reports).
Foundations of
Research
Descriptive research
1.
2.
3.
4.
Description11
Prediction
Theory
Application
EXAMPLE
Paleontology attempts to accurately
describe the predecessors of humans to
understand evolution
Carefully describing
specimens and the
conditions where they are
found can:
 Produce insights into
environmental change
and evolution
 Allow us to test
hypotheses & develop
theory.
Foundations of
Research



2. Science and Predictions
Practical
applications:
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 What test score best
predicts college success?
 Can I predict which
employees will steal?
These applications (should) stem from a theory.

Verbal & quantitative aptitude  academic success

A specific personality constellation  criminality…
That is (or should be…) supported by empirical evidence.
Foundations of
Research
Science and Predictions

Practical
applications:

Testing hypotheses:
1.
2.
3.
4.
Description13
Prediction
Theory
Application
 An hypothesis is a prediction
 Correlational research;
 I predict: cultures undergoing rapid economic change will be
more prone to irrational beliefs.
 Experimental research;
 Lab: make Experimental group socially uncertain.
 Control: simple distraction.
 I predict: experimental group more prone toward superstitious
beliefs.
Foundations of
Research
3. Developing & Testing Theory
Theory is the ‘bottom line’ of science
Identify basic (social, Ψ, physical…) processes…
that are systematically related…
that show how or why something works.
i.e., what “causes” a phenomenon in the natural world.
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EXAMPLE
Foundations of
Research
Predictions and theory development
New data have led us
to rethink basic
theories of human
evolution.
 From a simple
progression…
 …to a widening
“bush” of parallel
species.
1.
2.
3.
4.
Description15
Prediction
Theory
Application
EXAMPLE
Foundations of
Research
Predictions and theory development
As paleontologists
rethink the shape of
the evolutionary tree..
They reconsider the
basic processes that
shape human
evolution.
1.
2.
3.
4.
Description16
Prediction
Theory
Application
Foundations of
Research
Theory: Mediating variables
Mediating Variables:
 The core building blocks of theory,
 Basic physical, psychological or social processes,
 Tell us how or why things work,
 Help us explain our observations.
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Foundations of
Research
1.
2.
3.
4.
3. Testing theory: Mediating effects
Description18
Prediction
Theory
Application
Theory explains an observation or correlation by
invoking a mediating variable.
When are superstitions or irrational beliefs most common?
A. We describe a simple empirical effect (correlation):
Social & economic
uncertainty
Irrational
beliefs
Historically, superstitions are prevalent during times
of social & economic change.
Foundations of
Research
3. Testing theory: Mediating effects
1.
2.
3.
4.
Description19
Prediction
Theory
Application
Uncertainty and irrational beliefs…
A. We describe a simple empirical effect (correlation):
B. How does this work? What Theory(ies) may
explain this?
Uncertainty
✓
Need to feel
control
Irrational
beliefs
“Need for control” may Mediate the effect of uncertainty on
irrational beliefs.
 Social & economic uncertainty “causes” people to seek a
greater sense of personal control;
 Need for perceived control can “cause” people to adopt
superstitious beliefs.
Foundations of
Research
3. Testing theory: Mediating effects
1.
2.
3.
4.
Description20
Prediction
Theory
Application
Uncertainty and irrational beliefs…
How does this work? What Theory(ies) may explain this?
Uncertainty
✓
Need to feel
control
Irrational
beliefs
“Need for control” is a core Mediating Variable in this
theory.
It helps us explain how social & economic uncertainty
may make people vulnerable to superstitious beliefs.
Foundations of
Research
3. Testing theory: Mediating effects
1.
2.
3.
4.
Description21
Prediction
Theory
Application
Uncertainty and irrational beliefs…
How does this work? What Theory(ies) may explain this?
Uncertainty
✓
Need to feel
control
Irrational
beliefs
✓
Lessened
Critical
thinking
We may expand our theory:
Lessened critical thinking may also help explain
the effect of uncertainty on beliefs.
Foundations of
Research
3. Testing theory: Mediating effects
1.
2.
3.
4.
Description22
Prediction
Theory
Application
Uncertainty and irrational beliefs…
How does this work? What Theory(ies) may explain this?
Uncertainty
✓
Need to feel
control
Irrational
beliefs
✓
Lessened
Critical
thinking
This theory is comprised of two Mediating Variables:
The combination of these variables may well explain
the effect of uncertainty on beliefs.
Foundations of
Research
Theory and process
Uncertainty
✓
Need to feel
control
✓
Lessened
Critical
thinking
Theory:

...identifies basic economic / psychological
processes;
… is built of mediating variables;

…specifies how they may be related;

…generates testable hypotheses.

1.
2.
3.
4.
Description23
Prediction
Theory
Application
Irrational
beliefs
Foundations of
Research
1.
2.
3.
4.
Theory and process
Uncertainty
Need to feel
control
Description24
Prediction
Theory
Application
Irrational
beliefs
Lessened
Critical
thinking
I hypothesize that
I hypothesize that
creating uncertainty in
systems that
Theory:
a lab
will lessen
introduce critical
participants’ ability to
thinking in 1o and 2o
question
their own
school will have a
 ...identifies basic economic / psychological processes;
assumptions and
lower prevalence of
evaluate
evidence…
superstitious beliefs.
 … is built
of mediating variables;
An
tested
with
 hypothesis
…specifies
how
an experimental design.

they may be related;
…generates testable hypotheses.
An hypothesis tested with a
correlational design.
Foundations of
Research

4. Applications of theory
Use theory to design interventions
Educational theory:
Design of this course
 Being active
 Cognitive “chunking”
 Multi-media  attention

1.
2.
3.
4.
…an intervention study can test a theory
Behavioral or biomedical interventions  compare
treatments based on differing theories.
Description25
Prediction
Theory
Application
EXAMPLE
Foundations of
Research
Theories and interventions
1.
2.
3.
4.
Smoking & social
networks: people
are influenced by
their friends’
smoking
Intervention study of smoking
cessation: quitting with friends may be
more effective.
Description26
Prediction
Theory
Application
Foundations of
Research
Theories and interventions
EXAMPLE
Theory: social networks
 smoking.
Hypothesis: networkbased program would
work better.
Testing the hypothesis:
 Pointed to a practical intervention approach;
 Supported the theory.
1.
2.
3.
4.
Description27
Prediction
Theory
Application
Foundations of
Research
The values of science & empiricism
 Empirical description
 Qualitative vs. quantitative…
 Developing hypotheses.
SUMMARY
 Predictions
 Core feature of a hypothesis;
 Force us to clearly test our ideas.
 Developing and testing theory
 Central to science; explain how a natural process works.
 Applications of theories
 Expand and elaborate a theory.
 Advances in, e.g., technology, behavioral science
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Foundations of
Research

Elements of science, review 1
Epidemiology is…
A. A way of classifying people or behaviors
B. The study of how frequent a behavior or
“condition” is across a population.
C. The identification of basic psychological
principles that underlie important behaviors
D. A core feature of a hypothesis.
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Foundations of
Research

Elements of science, review 2
A Theory is…
A. A way of classifying people or behaviors
B. The study of how frequent a behavior or
“condition” is across a population.
C. The identification of basic psychological
principles that underlie important behaviors
D. A core feature of an hypothesis.
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Foundations of
Research

Elements of science, review 2
A mediating variable is…
A. A way of describing the world.
B. An observed correlation.
C. A psychological process that is the building
block of a theory.
D. A way of testing an hypothesis.
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Foundations of
Research

Elements of science, review 3
A Prediction is…
A. A way of classifying people or behaviors
B. The study of how frequent a behavior or
“condition” is across a population.
C. The identification of basic psychological
principles that underlie important behaviors
D. A core feature of a hypothesis.
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Foundations of
Research

Elements of science, review 4
A Taxonomy is…
A. A way of classifying people or behaviors
B. The study of how frequent a behavior or
“condition” is across a population.
C. The identification of basic psychological
principles that underlie important behaviors
D. A core feature of a hypothesis.
33
Foundations of
Research

Introduction to science, 5
What does science do?

Core features
of a research
study.

Overall Research approaches.
34
Foundations of
Research
35
The overall “flow” of research
Phenomenon
- Larger question the research addresses
Section Overview
Theory
- Explanatory processes & how
they are related
Hypothesis
- Concrete variables
-Specific prediction
Methods / Data
- Operational definitions
- Study procedures
Results
- Hypothesis-wise analysis of
outcomes
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
Foundations of
Research
36
Research Flow
Phenomenon
- Larger question the research addresses
What needs explaining?
Why is it important?
Theory
How / why do I
think it works?
- Explanatory processes & how
they are related
Hypothesis
- Concrete variables
-Specific prediction
What concrete evidence
or data will I collect?
What is my specific
prediction?
Methods / Data
- Operational definitions
- Study procedures
Results
- Hypothesis-wise analysis of
outcomes
What do the results
mean for the theory?
What is unanswered?
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
What was the outcome?
Hypothesis supported?
Foundations of
Research
37
Research Flow
The research flow
begins with broad,
abstract questions
Phenomenon
- Larger question the research addresses
Theory
- Explanatory processes & how
they are related
Hypothesis
- Concrete variables
-Specific prediction
Methods / Data
- Operational definitions
- Study procedures
Results
Then back to a
more general
discussion.
- Hypothesis-wise analysis of
outcomes
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
Gets more specific &
concrete
Foundations of
Research
Core features of research: Theory.
Phenomenon
- Larger question the research addresses
Theory
- Explanatory processes & how
they are related
Hypothesis
- Concrete variables
-Specific prediction
Theory:
Methods / Data
- Operational
definitions
 Abstract statement
of how
basic processes relate
to each other…
- Study procedures
Results
 …how or why the
phenomenon
- Hypothesis-wise
analysis of“works.”
outcomes
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
38
Foundations of
Research
39
Theory
Basic physical or
behavioral processes are
the building blocks of
theories.
 Economic uncertainty
 Cognitive style
 Stress
 Gravity
 Learning…
Foundations of
Research
40
Theory
They are abstract:
 Economic uncertainty
 We cannot actually “see”
 Cognitive style
gravity.
 We just see what it does
(stuff falls).
 Stress
 Gravity
 Learning…
Foundations of
Research
41
Theory
Gravity is a Hypothetical
Construct:
 Economic uncertainty
 Central to our
 Cognitive style
understanding of nature.
 Abstract; we cannot
measure it directly.
 We measure and
understand it by observing
its effects on the world.
 Stress
 Gravity
 Learning…
Foundations of
Research
Theory
42
Foundations of
Research
How do we use theory in research?

Test a theory:
Do women who feel strong stereotype threat about math
actually do worse?

Compare theories:
Which best explains women’s statistics performance:
stereotype threat or social role learning?

Extend an established theory:
Can stereotype threat help us explain athletic as well as
academic performance?

Apply a theory:
Can I create instructions that relieve stereotype threat for
women during statistics?
43
Foundations of
Research
Core features of research: Hypotheses.
Phenomenon
- Larger question the research addresses
Theory
- Basic Ψ processes we think explain
the phenomenon
Hypothesis
- Concrete variables that
express the Ψ processes
- Specific prediction
Hypothesis:
Methods / Data
- Operational definitions
- Study procedures
 A prediction
Results
- Hypothesis-wise
 Derived from / testing
thestatistical
theory
analysis of study outcomes
 That is potentially
falsifiable.
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
44
Foundations of
Research
Hypothesis

An hypothesis is a Prediction

Relating variables derived from the theory.


Specifies cause and effect.
…that is potentially falsifiable (see text for discussion)

Can be conceivably / logically shown to be untrue

Specific enough to be tested
45
Foundations of
Research
Hypothesis
Hypotheses: Measurement v. Experimental studies

In experiments we manipulate the Independent Variable.

Hypotheses are expressed in control terms:

IF I make people relaxed then their fear and loathing of
statistics will decrease.

Measurement studies do not manipulate anything.

Hypotheses are expressed as a relation.


People who are high on a measurement of relaxation will tend
to fear statistics less;
I predict a correlation between relaxation & fear of stats.
46
Foundations of
Research
Core features of research: Methods.
Methods:
Phenomenon
- Larger question the research addresses
Theory
 We attempt to make
term
ofexplain
the study as
- Basic each
Ψ processes
we think
objective as possible. the phenomenon
Hypothesis
 Both measurement -&Concrete
experimental
variables that
the Ψ processes
procedures rely on express
Operational
Definitions
- Specific prediction
Methods / Data
- Operational definitions
- Study procedures
Results
- Hypothesis-wise statistical
analysis of study outcomes
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
47
Foundations of
Research
Methods
 Turn our hypotheses into concrete
variables
 That we examine via specific procedures

Core element of scientific approach

Objective; designed to separate data from person

Public: multiple people participate in, challenge, or use
scientific findings

Replicable: others can repeat or expand the study
48
Foundations of
Research

49
Methods
We turn our hypotheses into variables via an
operation definition.
What is “depression”?
What operations could assess it?
Verbal behavior
Depression
Appearance
“vegetative”; sleep, eating
Suicidality, drug use, work…
Survey / questionnaire answers…
Foundations of
Research

Methods
Our Operation definition determines what a
variable “means” in our study.
What is “economic uncertainty”?
 The unemployment rate?
 Subjective attitude ratings?
What is “Stress”?
 Heart rate & cortisol levels?
 Speech patterns?
50
Foundations of
Research
51
Methods

This is the independent variable

To test the hypothesis that stress impairs memory I
may create stress in the lab via…
 Shock.
 Requiring a difficult performance in front of others.
Are
shock (a physical threat)
and
performance (a social threat)
Equivalent
‘Stressors”?
Foundations of
Research

52
Methods
I may measure stress levels in this class via:
 A questionnaire scale
 Heart rate
 Anxious behavior, sleep loss, appetite change…
Are
Heart rate
and
sleep loss
Equivalent
measures of
Stress?
Foundations of
Research
53
Operationalizing “Stress”
Does stress lead to illness?
EXAMPLE
“Stress”
“Illness”
Measure the dependent
Experimental Manipulate the
variable
independent variable
design
 Threatening
information.
 Infection postexposure
 Shock.
 Observed respiratory
infections
 Require difficult public
performance.
Measurement Measure the predictor
study
 Questionnaire scale
on life events
 Assess cardiovascular reactivity
Measure the outcome
variable
 Self-reported
respiratory infections
 Morbidity & mortality
Foundations of
Research


Methods: Why use Operational Definitions?
Any theory must be operationalized to be heuristically
useful
Operational definitions  real observable world.
I think stress makes people less healthy

What does “stress” mean?
 How will you measure it?

What does “health” mean?
 How will you measure it?
 Think critically about what each variable means.
54
Foundations of
Research


Some variables are easy to operationalize; e.g., the
effect of a drug dose on hypertension.

IV = drug dose1 v. drug dose 2 v. Placebo…

DV = blood pressure.
Some constructs can only be roughly operationalized.



Methods: The limits of Operational Definitions
“Pro-social attitude”, “self-concept”…
Some constructs have diverging operational definitions.

How do you operationally define “stress”?

…learning?
Behavior?
Self-perception?
Physiological?
Some domains may not be operationalizable.


String theory…
“Spirituality”? “Happiness”?
55
Foundations of
Research

EXAMPLE



When am I dead?
56
Middle ages: the soul departs the body –
weighs 21 grams
The name:
• Physical death
• Your body is consigned to the grave
• Someone speaks your name the last time
17th Century: Cordelia’s daughter in King Lear shows no
breath on a mirror held to her nose
19th Century: Development of the stethoscope and “heart
death”.

Mid-20th Century: Development of respirators / life support
and “brain death”.

21st Century: fMRI images show responsiveness
even in some “vegetative” patients
Foundations of
Research
Core features of research: Results.
Phenomenon
- Larger question the research addresses
Theory
- Basic Ψ processes we think explain
the phenomenon
Results:
Hypothesis
- Concrete variables that
express the Ψ processes
- Specific prediction
 Qualitative
 Quantitative; statistical
Methods /reasoning
Data
- Operational definitions
- Study procedures
Results
- Hypothesis-wise statistical
analysis of study outcomes
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
57
Foundations of
Research
Results:
Two major streams:
Qualitative research  rich description
 Text,
 Images,
 Video…
Quantitative research  hypothesis tests
 Numerical scales
 Statistical reasoning
58
Foundations of
Research
Results:
Quantitative research.

Numerical representation of reality

Descriptive statistics


Inferential statistics


Simple characterization: “who / what / when?”
Generalize to a larger population.
“Statistical reasoning”:
Probability judgments
using the Normal
distribution.
59
Foundations of
Research
Core features of research
Phenomenon
- Larger question the research addresses
Theory
- Basic Ψ processes we think explain
the phenomenon
Hypothesis
- Concrete variables that
Discussion & Conclusions:
express the Ψ processes
- Specific prediction
Methods / Data
 Implications for theory?
- Operational definitions
 Study limitations?- Study procedures
Results
 Where now? - Hypothesis-wise statistical
analysis of study outcomes
Discussion & Conclusion
- Relate results back to theory
- Study limitations & Future studies
60
Foundations of
Research
Discussion
Study implications.

What does it mean that the hypothesis was (was
not) supported?

Change / modify theory?

Other interpretations / hypotheses?

Applications?
 Critical Thought about the meaning – and alternate
interpretations – of our results.
61
Foundations of
Research
Discussion
Study limitations.

Boundaries on what this study can tell us?


Internal validity:

Well did we represent the hypothetical constructs…?

Quality / nature of operationalization & design?
External validity: How representative was…

Our sample?

Manipulation / measurement of the independent variable(s)?

Assessment of the dependent variable(s)?

The research setting itself.
62
Foundations of
Research
Phenomenon & Theory
Hypothesis
SUMMARY
63
What does science do?
Methods
Results
Discussion
 Hypothetical constructs
 In important relationship
 Specific variables
 Falsifiable prediction
 Operational definition
 Internal & external validity
 Qualitative / Quantitative
 Descriptive question or exploration
 Hypothesis test
 Meaning of results for the theory
 Alternate interpretations
 Study Limitations.
Foundations of
Basic
Research
64
Elements of a Research Project
Phenomenon
Big picture / question
Theory
Hypothetical Constructs
Causal explanation
Hypothesis
Begin with the “big question”
… articulate a clear theory
…derive concrete hypotheses.
Operational definition
Specific prediction
Methods
Measurement v.
experimental
Specific methods &
operational definitions
Data / Results
Actual data & results…
• Descriptive data
• Test hypothesis
Discussion
… implications for the theory
Implications for theory
Conclusions
Future research?
…and larger issues.
Foundations of
Basic
Research
65
Elements of a Research Project
Phenomenon
Big picture / question
Theory
Hypothetical Constructs
Causal explanation
Hypothesis
Operational definition
Specific prediction
Methods
Measurement v.
experimental
Data / Results
• Descriptive data
• Test hypothesis
Discussion
Implications for theory
Conclusions
Future research?
Each element of the
project corresponds to a
later / earlier issue…
Foundations of
Basic
Research
Elements of a Research Project
Study results often lead to
the next experiment…
66
Phenomenon
Big picture / question
Theory
Hypothetical Constructs
Causal explanation
2. …what don’t we
understand?
3. …explanation?
Hypothesis
Operational definition
Specific prediction
4. Theory  hypothesis
Methods
Measurement v.
experimental
5. …how do we test or
measure it?
Data
//Results
Data
Data
Results
• Descriptive
data
•Test hypothesis
Descriptive
data
Test hypothesis
or•observation
Discussion
Implications for theory
Conclusions
Future research?
1. Observation or hunch
Then we run the rest of the
process
Foundations of
Basic
Research
67
Elements of a Research Project
Phenomenon
Big picture / question
Research results  new
experiment or study.
Theory
Hypothetical Constructs
Causal explanation
Hypothesis
1. Alternate hypotheses?
Unanswered questions?
Operational definition
Specific prediction
Methods
Measurement v.
experimental
Data
/ Results
Results
• Descriptive
data
Test
newhypothesis
hypothesis
Was
the
• Test hypothesis
supported?
Discussion
Implications for theory
Conclusions
Future research?
2. Negative results:
 Reframe hypothesis…
 …operational definitions
3. Run follow-up study.
Foundations of
Basic
Research
68
Elements of a Research Project
Phenomenon
Big picture / question
Theory
Hypothetical Constructs
Causal explanation
1. Findings may lead us to
rethink our theory.
Hypothesis
Operational definition
Specific prediction
Methods
Measurement v.
experimental
Results
Other findings
Data
/ Results
Results
Data
/ Results
•
Descriptive
data
Our new
initial
findings
Test
hypothesis
• Test hypothesis
Discussion
Implications for theory
Conclusions
Future research?
2. We:
 Formulate different
hypotheses
 Different study design &
variables
 New results
Foundations of
Basic
Research
69
Elements of a Research Project
Phenomenon
Big picture / question
Theory
Hypothetical Constructs
Causal explanation
Hypothesis
Operational definition
Specific prediction
Methods
Measurement v.
experimental
Data / Results
• Descriptive data
• Test hypothesis
Discussion
Implications for theory
Conclusions
Future research?
Key elements of research:
 Not a simple linear
process.
 All elements interact.
Foundations of
Research
Elements of science, review 1
A hypothetical construct is:
A = A concrete description of a
variable
B = An abstract statement about a
ψ process that cannot be seen
directly.
C = An excuse you construct to
explain why you are late.
D = An abstract use of statistical
theory to test a hypothesis.
70
Foundations of
Research
Elements of science, review 2
A theory is:
A = Wild-eyed speculation about
some topic that most people are
not interested in.
B = An authoritative statement of
how something works: truth.
C = Always tentative or provisional.
D = A statement about how two (or
more) hypothetical constructs are
related.
71
Foundations of
Research
Elements of science, review 3
An operational definition is:
A = The specific way we
manipulate an independent
variable.
B = A surgical procedure we use to
test a hypothesis.
C = The particular procedures we
use to measure a study variable.
D = An abstract statistical
statement using probability
theory to test hypotheses.
72
Foundations of
Research

Elements of science, review 3
In science the numbers are
what count most.
A. Yes, if I have enough of them
B. Yes, if they have been
operationally defined
C. No, the measures are most
important
D. No, the Theory and hypothesis
is most important.
73
Foundations of
Research
Introduction to science, 6

What does science do?

The core features of a
research study.
Overall

Research
approaches.
74
Foundations of
Research
Overall research strategies
Observation or Measurement
Simple Description
Qualitative
‹#›
75
Quantitative
Correlational
Studies
Experiments
Quasiexperiments
Measurement
studies vs.
Experiments
“True”
experiments
Foundations of
Research
Overall research strategies
Observation or Measurement
Simple Description
Qualitative
‹#›
76
Quantitative
Correlational
Studies
Assess nature
 Describe behavior
 Test hypotheses
Experiments
Quasiexperiments
“True”
experiments
Exert control over
nature
 Test experimental
predictions
(hypotheses).
Foundations of
Research
Overall research strategies
Observation or Measurement
Simple Description
Qualitative
Explore
behavior.


Rich /
detailed
description.
Often
targeted
samples.
‹#›
77
Quantitative
Describe
trends.


Count
behaviors
e.g., by age,
gender,
ethnicity...
Archival data
Experiments
Correlational
Studies
Quasiexperiments
“True”
experiments
Relate
variables
Field studies
Controlled
(“lab”)
conditions.


Measured
variables
Natural
events
Experiments:
Test or
generate
No control
hypotheses.
over IV
Nonequivalent
Groups

Manipulate
Independent
Variable

Measure
Dependent
Variable.

Control all
aspects of
experiment
Foundations of
Research
Overall research strategies: Drug use
Observation or Measurement
Simple Description
Qualitative
Quantitative
Correlational
Studies
‹#›
78
Experiments
Quasiexperiments
“True”
experiments
Research
Question:
Research
Question:
Research
Question:
Research
Question:
Research
Question:
Mechanics of
drug use.
Epidemiology
of drug use.
Social / ψ
variables in
drug use.
Compare drug
treatments.
What brain
centers control
“drug craving”?
Methods:
Methods:
Methods:
Methods:
Methods:
 Directly
observe
 drug markets,
 In-depth
interviews
 drug users,
 Police…


Surveys,
interviews,
archival data
Show simple
frequencies
across, e.g.,
groups.

Surveys or
interviews
 Experimental
design.

Archival data

Test
hypotheses by
correlating
specific
variables.
 Groups are
non-equivalent
not blind
not randomly
assigned…

Stimulate
contrasting
brain areas
(IV).

Assess drugseeking (DV).
Foundations of
Research
79
Experiments
Controlled experiments:
“Gold standard” for testing hypotheses.
Participant
Selection
Group
Assignment
Experimental
group 
Experimental
Procedures
Experimental
Condition
Results
Procedure 
Experimental
/“Treatment”
condition
 Outcome
Procedure 
Control /
placebo
condition
 Outcome
Sample
Control
group 
Random
sample of the
target
population.
Randomly
assign
participants to
groups.
Exactly equal
study
procedures X
groups.
Impose
experimental
manipulation
Independent
Variable.
Assess
Dependent
Variable.
Foundations of
Research
80
Experiments
Controlled experiments:
“Gold standard” for testing hypotheses.
Participant
Selection
Group
Assignment
Experimental
group 
Sample
Control
group 
Random
sample of the
target
population.
Randomly
assign
participants
to groups.
Experimental
Procedures
Experimental
Condition
Results
Experimental
Random assignment
/“Treatment”
 Outcome
(Rather than, e.g., condition
using existing groups…)
Procedure 
/
ensures groups Control
are equivalent
at
Procedure 
placebo
 Outcome
baseline.
condition
Exactly equal
study
procedures X
groups.
Impose
experimental
manipulation
Independent
Variable.
Assess
Dependent
Variable.
Foundations of
Research
81
Experiments
Controlled experiments:
“Gold standard” for testing hypotheses.
Participant
Selection
Group
Assignment
Experimental
group 
Experimental
Procedures
Procedure 
Sample
Control
group 
Random
sample of the
target
population.
Randomly
assign
participants to
groups.
Experimental
Condition
Results
Experimental Control
Experimental
/“Treatment”
 Outcome
ensures
groups
have the
condition
same procedures.
Procedure 
Control /
placebo
condition
Exactly
equal study
procedures
X groups.
Impose
experimental
manipulation
Independent
Variable.
 Outcome
Assess
Dependent
Variable.
Foundations of
Research
82
Experiments
Controlled experiments:
“Gold standard” for testing hypotheses.
Participant
Selection
Sample
Random
sample of the
target
population.
Group
Assignment
Experimental
Procedures
Manipulating
Experimental the
Procedure 
group 
Independent
Variable
ensures that we (the
Control
experimenter)
cause the
Procedure
group 
experimental
effect.
Randomly
assign
participants to
groups.
Exactly equal
study
procedures X
groups.
Experimental
Condition
Results
Experimental
/“Treatment”
condition
 Outcome
Control /
placebo
condition
 Outcome
Impose
experimental
manipulation
Independent
Variable.
Assess
Dependent
Variable.
Foundations of
Research
83
84
Foundations of
Research

Often true experiments are
not possible:

We must use existing groups

We cannot control all the
procedures

We cannot manipulate the
Independent Variable….
Observation or Measurement
Simple Description
Qualitative
Quantitative
Correlational
Studies
Experiments
Quasiexperiments
 Examples:  Naturally occurring events;
 Education research;
 Public health research.
“True”
experiments
Foundations of
Research
85
Measurement v. experiments
Observation or Measurement
Simple Description
Qualitative
Quantitative
Explore
Describe
Experiments
Correlational
Studies
Quasiexperiments
“True”
experiments
Relate measured
variables
Field studies.
Test specific
hypotheses
Experiment
High control / ‘lab’
conditions
Internal
validity
Determine “cause and
effect”: validly interpret
data
Measurement
Less control;
‘research in nature’
External
validity
Data can generalize to
“real world” & capture
more complexity
Foundations of
Overall Research strategies:
Research
‹#›
86
Validity
Observation or Measurement
Simple Description
Qualitative
Quantitative
Explore
Describe
Experiments
Correlational
Studies
Quasiexperiments
“True”
experiments
Relate measured
variables
Field studies.
Test specific
hypotheses
External validity
Internal validity
Less control:

Observe / test phenomenon
under natural conditions.

More accurate portrayal of:
 “how it works in nature”
More control:

Isolate (or create) the
phenomenon in a controlled
environment

Addresses specific questions
or hypotheses

More able to interpret cause &
effect
 complexity of phenomenon

Less able to interpret cause &
effect
87
Foundations of
Research
Overview
Foundations of
Research
88
Core course topics
How do we know things?

What does scientific method tell us that other
methods (political, religious thought) do not?
What does science do?

Describe the world





Taxonomies
Epidemiology
Qualitative research
Test theories



Predict events



Simple predictions
Correlational studies
Experiments

Cause & effect
Identify basic processes
Show how processes are
related
Test applications of
theories

E.g., behavioral interventions
Foundations of
Research
key terms
Features of research: Key terms

Theory

Hypothetical construct

Hypothesis

Variable

Operational definition

Experimental control

Measurement v. experimental studies

Internal & external validity
89
Foundations of
Basic
Research
Elements of a Research Project
Phenomenon
Big picture / question
Theory
Hypothetical Constructs
Causal explanation
Hypothesis
Operational definition
Specific prediction
Methods
Measurement v.
experimental
Data / Results
• Descriptive data
• Test hypothesis
Discussion
Implications for theory
Conclusions
Future research?
90
Foundations of
Research
Observation or Measurement
Simple Description
Qualitative
Explore the actual
process of a
behavior.
91
Basics of major forms of research.
Quantitative
Describe a
behavioral or
social trend.
External validity
Experiments
Correlational
Studies
Quasiexperiments
“True”
experiments
Relate measured
variables to each
other to test
hypotheses.
Test hypotheses
in naturally
occurring events
or field studies.
Test specific
hypotheses via
controlled “lab”
conditions.
Internal validity