Diagnostics in pedagogy and psychology very often requires measurement of properties (theoretical constructs) that are not directly observable and are therefore represented by manifest indicators. The simple sum of the results in individual indicators serves in many cases as an estimate of the latent construct.
Structural equation modeling (SEM) on the other hand offers a possibility to control the relative importance of indicators in the composite score. Gender differences in intrinsic motivation (measured by The Sport Motivation Scale) were examined in a sample of 456 university students.
Using an independent-group t-test, two types of sum score (simple sum vs. SEM based sum) were compared.
We presented some important features of SEM that might have substantial impact on interpretation of our results and therefore we may recommend SEM as a very useful tool in analysis of between-group differences especially in situations when measuring latent theoretical constructs.