2. OUTLINE
Introduction
Causation in the Social Science
Validity and Causal Inference
Units of Analysis
The Time Dimension
How to Design a Research Project
The Research Proposal
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•Causation, units, and time are key elements in
planning a research study
•As social scientists, we seek to explain the causes
of some phenomenon (e.g., crime)
•Often, criminal justice researchers want to find out
something that involves questions of cause and
effect
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•Causation is the focus of explanatory research
•Cause in social science is inherently
probabilistic
•Certain factors make crime/delinquency more or
less likely within groups of people
•Two models of explanation
•Ideographic – Lists the many, perhaps unique
considerations behind an action
•Nomothetic – Lists the most important (and
fewest) considerations/variables that best explain
general patterns of cause and effect
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•Assessing an idiographic explanation – posited
by Maxwell (2005)
•How credible and believable it is
•Whether alternative explanations (“rival hypotheses)
were seriously considered and found wanting
•Assessing a nomothetic explanation – posited by
Shadish, Cook, & Campbell (2002)
•Empirical relationship between variables
•Temporal order (cause precedes effect)
•No alternative explanations – no spurious other
variable(s) affecting the initial relationship
•Any relationship that satisfies all these criteria is
causal
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•Within the probabilistic model, two types:
•Necessary cause – Represents a condition that
must be present for the effect to occur (being
charged before being convicted)
•Sufficient cause – Represents a condition that, if it
is present, will pretty much guarantee that the
effect will occur (pleading guilty before being
convicted)
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•Scientists assess the truth of statements
about cause by considering threats to validity.
•When we make a cause-and-effect statement,
we are concerned with its validity – whether it
is true and valid
•Certain threats to the validity of our inference
exist
•These are reasons why we might be incorrect
in stating that some cause produces some
effect
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•Refers to our ability to determine whether a
change in the suspected cause is statistically
associated with a change in the suspected
effect
•Are two variables related to each other?
•Researchers cannot have much confidence in
statements about cause if their findings are
based on a small number of cases
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•An observed association between two
variables has internal validity if the relationship
is, in fact, causal and not due to the effects of
one or more other variables
•Generally due to non-random or systemic
error
•The threat to IV results when the relationship
between two variables arises from the effect of
some third variable
•Example: drug users sentenced to probation
over prison recidivate less
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•Concerned with whether research findings in
one study can be replicated in another study,
often under different conditions
•Do the findings apply equally in different
settings (locales, cities, populations)?
•Kansas City evaluation found sharp reductions
in gun-related crimes in hot spots that had
been targeted for focused police patrols
•Indianapolis and Pittsburgh launched similar
projects
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•Concerned with how well an observed
relationship between variables represents the
causal process
•Refers to generalizing from what we observe
and measure to the real-world things in which
we are interested
•e.g., close supervision of officers more
tickets?
•e.g., Kansas City Preventive Patrol Experiment,
“police visibility”
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•The four types of validity threats can be
grouped into these two categories
•Bias – Internal Validity and Statistical
Conclusion Validity threats are related to
systematic and nonsystematic bias
•Generalizability – Construct Validity and
External Validity are concerned with
generalization to real-world behaviors and
conditions
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•Temporal order: which comes first?
•A statistical relationship exists, but underlying
causes affect both drug use and crime
(Internal Validity threat)
•What constitutes drug use? Crime?
(Construct Validity threat)
•How will policy affect drug use and crime?
•A crackdown on all drugs among all
populations will do little to reduce serious crime
14. •Bridges idiographic and nomothetic
approaches to explanation by seeking to
understand how causal mechanisms operate in
specific contexts
•Studies how such influences are involved in
cause-and-effect relationships
•Exhibits both ideographic & nomothetic
approaches to explanation
•"Can the design of streets and intersections be
modified to make it more difficult for street
drug markets to operate?"
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•What or who is studied
•Individuals - Police, victims, defendants,
inmates, gang members, burglars, etc.
•Groups - Multiple persons with same
characteristics (gangs, cities, counties, etc.)
•Organizations - Formal groups with established
leaders and rules (prisons, police departments,
courtrooms, drug treatment facilities, etc.)
•Social artifacts - Products of social beings and
their behavior (stories in newspapers, posts on
the Internet, photographs of crime scenes,
incident reports, police/citizen interactions)
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•Ecological fallacy - Danger of making
assertions about individuals based on the
examination of groups or aggregations
•Poor areas = more crime, therefore poor people
commit more crime
•Individual fallacy – Using anecdotal evidence to
make an argument
•O.J. Simpson court resources
•Reductionism - Failing to see the myriad of
possible factors causing the situation being
studied
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•Time sequence is critical in determining
causation
•Time is also involved in the generalizability of
research findings
•Observations can either be made more or less
at one point, or stretched over a longer period
•Observations made at more than one time point
can look forward or backward
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•Observing a single point in time (cross-section)
•Simple and least costly way to conduct
research
•Typically descriptive or exploratory in nature
•A single wave of the National Crime
Victimization Survey (NCVS) is a descriptive
cross-sectional study that estimates how many
people have been victims of crime in a given
time
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•Permit observations over time
•Trend – Those that study changes within
some general population over time (UCR)
•Cohort – Examine more specific populations
as they change over time (Wolfgang study)
•Panel – Similar to trend or cohort, but the
same set of people is interviewed on two or
more occasions (NCVS) (panel attrition)
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•Gun ownership and violence study by Swiss
researcher Martin Killias (1993)
•Compared rates of gun ownership as reported in
an international crime survey to rates of
homicide and suicide committed with guns
•May be possible to draw approximate
conclusions about processes that take place
over time, even when only CS data is available
•When time order of variables is clear, logical
inferences can be made about processes taking
place over time
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•Asks people to recall their past for the purpose
of approximating observations over time
•People have faulty memories; people lie
•Analysis of past records also suffer from
problems – records may be unavailable,
incomplete, or inaccurate
•Prospective research – longitudinal study that
follows subjects forward in time (Widom – child
abuse/drug use)
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•Cross-sectional study = snapshot – an image
at one point in time
•Trend study = slide show – a series of
snapshots in sequence over time, allows us to
tell how some indicator varies over time
•Panel study = motion picture – gives
information about individual observations over
time
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•Designing research requires planning several
stages, but the stages do not always occur in
the same sequence
•Beginning points for a line of research
•e.g., interests, ideas, theories, new programs
•Why does something occur?
•Why is this how it is?
•What about this possible program?
•These questions may lead to others you might
like to explore
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•Find out what research has been done
•Read newspaper stories, journal articles, check
out the Internet, talk to relevant people
•Figure out your objective & intended audience
•Generally, your purpose for undertaking
research can be expressed in a report
•You should be clear about the kinds of
statements you will want to make when the
research is complete
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•Specify what you mean by the term in your
research - this doesn't necessarily mean you
have to settle for a single definition
•What do you mean by the concept being
studied?
•If you are going to study fear of violent crime:
•What is considered “violent crime”?
•What is considered “fear”?
•You need to specify ALL the concepts you wish
to study
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•A variety are available, each has strengths and
weaknesses, choose one after considering the
specific concept you want to study
•Interviews, surveys, field research, content
analysis, official records
•The best studies utilize more than one research
method
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•Create concrete ways of actually measuring
your concept
•Fear and violent crime:
•Questionnaire item: how safe do you feel in
your house, downtown at night, etc.
•Official records of violent crime incidents in that
neighborhood, downtown, etc.
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•Exactly who or what will you study?
•Population – Group (e.g., of people) about
whom we want to be able to draw conclusions
•Since it is generally unfeasible to study ALL
members of that population, how will you take a
representative sample?
•Fear and violent crime: Will you include
elderly? Teenagers and kids? A particular race or
gender?
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•Collect the empirical data
•Make the observations that you will process,
analyze, interpret, apply, and review
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•You have amassed a volume of observations in
a form that usually is not easily interpretable
•How will you make sense of the observations?
•Code the data somehow
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•Manipulate the data
•Goal is to draw conclusions that reflect on the
interests, ideas, and theories which initiated our
research project
•Calculate percentages of those who have been
victimized by violent crime, those who fear
violent crime, differences among population
subsets, etc.
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•Utilize the research you’ve conducted and the
conclusions you’ve reached
•Make your findings known to others
•Develop policy to address your findings
•Determine what mistakes were made that
could be corrected in the future
•Determine how your research might feed into
future research
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•Begin by assessing:
•Your interests
•Your abilities
•The resources available to you
•What are you interested in studying?
•What information is needed & how to obtain it
•Review prior research in journals, books and
governmental reports
•“Triangulation”
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•Problem/Objective •Data Collection
Methods
•Literature Review
•Analysis
•Research Questions
•References
•Subjects for Study
•Schedule
•Measurement
•Budget