Creswell_Research_Design_ Qualitative Quantitative and Mixed Methods Approaches 2018 5th Ed

positive or negative valences that postulate or infer relationships.
Use two-headed arrows connected to show unanalyzed relationships between variables not dependent
upon other relationships in the model.
More complicated causal diagrams can be constructed with additional notation. This one portrays a basic
model of limited variables, such as typically found in a survey research study.
A variation on this theme is to have independent variables in which control and experimental groups are
compared on one independent variable in terms of an outcome (dependent variable). As shown in Figure 3.2,
two groups on variable X are compared in terms of their influence on Y, the dependent variable. This design is
a between-groups experimental design (see Chapter 8). The same rules of notation previously discussed apply.
Figure 3.1 Three Independent Variables Influence a Single Dependent Variable Mediated by Two
Intervening Variables
Figure 3.2 Two Groups With Different Treatments on X Are Compared in Terms of Y
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