model. For this study a model was identified based on previous findings and hypotheses
in the literature.
In a path diagram, observed or measured variables are represented as rectangles,
whereas latent variables that have been derived are represented as circles or ovals.
Relations between variables in SEM, whether the variables are latent or measured are
represented by path diagram, with collections of variables connected by lines and arrows.
Variables with lines having one-way arrows pointed to them are dependent variables in
the model. In this model, one latent dependent variable, reading fluency, is indicated.
Variables that are the sources of lines with arrows and have no arrow leading into them
are independent variables. In this model, three latent independent variables are estimated:
phonological awareness, rapid-naming and visual skills. The curved arrow between latent
variables represents the covariance or correlation between the two independent variables
in predicting the dependent variables.
The overall model fit
The SEM requires that models be formally specified for estimation and model
testing (Hoyle, 1995). In terms of model testing, the first step estimates the goodness-of-
fit of the hypothesized research model. This is typically done using a chi-square (X2) to
determine if differences between the data and the model are statistically significant and
can evaluate the relative fit of models of differing complexity.