ABSTRACT
The data collection has been carried out within a combined longitudinal and cross-sectional design admitting both cross-sectional, longitudinal and diagonal analyses, thus making possible the analysis of three basic types of time-related effect: situational, maturational and cohort effects (Figure 3.2; see also Chapter 4). Since the data collection has been undertaken in two locations, we are in a position also to add spatial comparisons to the temporal ones. For logistical reasons the data collections in the two towns were as a rule undertaken during different semesters of the same school year.
