STRATEGIES OF RESEARCH DESIGN
prediction. Notice that we can reformulate and bet-
ter focus it now into: “Are couples who marry
younger more likely to divorce?”
We can create several hypotheses for one
research question. Another hypothesis from the
same research question is as follows: “The smaller
the difference between the ages of the marriage
partners at the time of marriage, the less likely that
the marriage will end in divorce.” In this case, we
specify the variable age at marriage differently.
We can have a hypothesis that specifies that a
relationship holds under some conditions but not
others. As Lieberson (1985:198) remarked, “In
order to evaluate the utility of a given causal pro-
position, it is important that there be a clear-cut
statement of the conditions under which it will
operate.” For example, a hypothesis states: The
lower the age of the partners at time of marriage,
the higher are the chances that the marriage will
end in divorce, unless it is a marriage between
Ecological Fallacy Error of Reduction
Teleology Tautology
Levels
of Analysis
Spurious Relationship
= researcher makes statements about this level
= researcher has evidence for this level
Not
measurable
Not earlier
in time
Variable 1 Variable 2
?
Variable 2
Variable 1
Variable 2
Variable 1 Variable 3
FIGURE 5 Five Errors in Explanation to Avoid