Good Researchers
1.
Understand Causality
One thing causes another when there is:
a) Association—things must vary together
b) Time Order—the thing that causes the other must
occur prior to the other
c) Nonspuriousness—relationship between two things is
not coincidental and caused by a third thing
d) A Mechanism—a plausible reason that one should
cause the other
e) A Context—specification of what conditions permit
or favor the causal relationship
c) Nonspuriousness—relationship between two things is
not coincidental and caused by a third thing
A spurious relationship is one where a third (extraneous)
variable causes two others to change at the same time,
making it look like they are related.
Education
Crime
Education
Crime
Size of City
Terms associated with “causality”
Independent Variable:
A thing we think causes changes in another thing.
Dependent Variable:
A thing we think changes in response to changes in another thing.
X
Independent
Variable
Y
Dependent
Variable
Terms associated with “causality”
Hypothesis
Research Hypothesis—based on theory, it is a statement of
what one expects to find after data are collected and
analyzed. A causal hypothesis specifies that an
independent variable causally related to a dependent
variable.
Null Hypothesis—a statistical terms for a statement of “no
difference,” which typically contradicts the research
hypothesis. This statement (typically that nothing is
happening that would support our expectations) is what
we are left with unless we find overwhelming evidence to
reject it. Statistical procedures typically test the null.
Good Researchers
2.
Test Ideas Against Empirical Reality
You are a sociologist, meaning that you attempt to
explain what actually occurs in the social world—not
what ought to occur or what The Divine intended to
occur.
3.
Plan and Carry Out Investigations Systematically
(marked by thoroughness and regularity)
Use good methods and statistics. Avoid salient cases
and anecdotal information
4.
Do not Become Personally Invested in their Results
Your beliefs and emotions may pick topics of interest, but
science demands dispassionate analysis
Good Researchers
5. Replicate Research and Build Social Theory
Your research must begin where the community
of scholars have left off. Everything must be
grounded in what has gone before.
So use others’ findings and theories!
Scholars should work to see if others’ findings
hold up.
Research Model
 Academic or Basic Research
Research Circle
Theory
Empirical
Generalizations
Hypotheses
Inductive
Deductive
Data
Research Model
► To
test hypotheses, we must use variables.
 A variable is a property of people or objects that can
take on two or more values.
► Sociologists
typically measure variables with questions,
observations, or officially collected information
► A variable appears in a data set along with other variables as a
set of numbers where each person or unit has a particular
number entered for its value on the property that the variable
measures
Measurement
To speak responsibly about our world, we
need ways to document and measure
what is out there.
In social sciences, measurement is
sometimes complex.
How do you define poverty?
Income level
Nourishment
Living conditions
Property
How should a researcher define poverty?
There is an official definition in the US:
Measurement
Measurement
“Operationalization” is the term used to denote the
ways concepts are measured to form variables.
For example:
► One can make observations.
► One
can use official information.
► One
can ask questions of respondents.
Measurement
► Concepts
become Numbers
 In quantitative research, we turn
responses to our “measuring
devices” (questions) into numbers.
This is called coding.
 This is just like using instruments in
other research to quantify concepts.
Measurement
Many concepts are measured with scales…
Indexes and Scales
A series of questions is used to more comprehensively
measure a concept than would be possible with a single
question. These are especially appropriate for
measuring concepts that we know exist but cannot see.
►
We know the following exist, but we cannot directly
view them:
Self-esteem
Well-being
Gender Identity
Depression
Index: Each item is equally weighed to create a sum or average
Scale: Some items add more value to the total measure than other items
Measurement
For Example, Researchers typically operationalize self-esteem by using the
Rosenberg Self-esteem Scale (which is technically an index).
Measurement
Coding for the Rosenberg
Self-Esteem Scale
Positive Items Includes:
Strongly Disagree = 1
Disagree = 2
Agree = 3
Strongly Agree = 4
The researcher enters the
number that corresponds
with each person’s
answer. Then adds up all
responses to from selfesteem score.
Measurement
Good measurement procedures are a topic for quantitative methods. In this class,
we will have to presume the data we use came from proper measures.
Even properly measured variables will introduce frustrations.
Be aware:
coding schemes are sometimes illogical and/or confusing


coding refers to the system used to assign numerical value to responses on variables
For example, a survey may use ‘0’ for Not Applicable, ‘8’ for No Answer, and so forth
each data set (or variable) has a “unit of analysis”—that is it represents
individuals’, groups’, or organizations’, or geographic areas’ characteristics. One
should never make statements about the wrong unit of analysis after
conducting statistical procedures.
each variable has a particular “level of measurement” that determines the kind
of statistical procedures you may use with it
Measurement
Levels of Measurement
One must know the nature of one’s variables in order to understand what
manipulations are appropriate (and later, which statistical tests to use because
they must be mathematically manipulated for statistics).
Nominal Level of Measurement
Ordinal Level of Measurement
Interval Level of Measurement
Ratio Level of Measurement
Measurement
Levels of Measurement
Nominal Level of Measurement
► Items or responses are
categorical. When assigned
numbers, the numbers have no
mathematical interpretation.
► A nominal variable classifies
persons, places or things
without implying any rank
among them.
For example:
Race:
Cars:
1=black
1=Chevy
2=white
2=Honda
It makes no sense to add, subtract, multiply, or divide these.
3=Asian
3=Ford
Measurement
Levels of Measurement
Ordinal Level of Measurement
► Items or responses are assigned to
categories along a dimension of types
with increasing value (or in order).
The numbers only indicate order, not
magnitude.
►
An ordinal variable ranks persons,
places or things, but there is no
accurate way to gauge the distance
between them.
For example:
Professor Rank:
Sexy Cars:
1=Assistant
2=Associate
1=Green Gremlin 2=Blue Impala
3=Full
3=Red Audi
It typically makes no sense to add, subtract, multiply, or divide these.
Sociologists, using good judgment, may.
Measurement
Levels of Measurement
Interval-Ratio Level of Measurement
► Interval:
An interval variable assigns persons, places or things to
a continuum that has specific intervals (of equal
magnitude) between units of measure, but does not
have an absolute zero point.
► Ratio:
A ratio variable notes the number of persons, places or
things on a continuum that has a zero point and has
specific intervals (of equal magnitude) between units of
measure. Units of measure denote quantity.
For example:
Self-Esteem:
Age:
Scale ranges from 10 to 40
1=1 year, 2=2years, 3=3years, etc.
It typically makes sense to conduct mathematical operations on these.
Measurement
While each variable we use has a number
assigned to responses, we must remember
whether the numbers are meaningful or not.
For nominal variables, the numbers are
meaningless. For ordinal variables, we sometimes
treat the numbers as meaningful if one can make
an argument for doing so.
Measurement
The special case of dichotomous variables:
A dichotomous variable can take one of two values.
For example:
Sex: 0=Male, 1=Female
Race: 0=Other, 1=Hispanic
Cars: 0=Other, 1=SUV
Are dichotomous variables nominal, ordinal, or intervalratio?
Measurement
► What
level of measurement for this GSS
variable?
Measurement
► What
level of measurement for this GSS
variable?
Measurement
► What
level of measurement for this GSS
variable?
Measurement
► What
level of measurement for this GSS
variable?
Measurement
► What
level of measurement for this GSS
variable?