# Testing a New Structured Tool for Supporting Requirements' Formulation and Decomposition
## 4 Discussion  
### Obtained Results  
By looking at the total number of generated requirements, the differences between control group and analysis group are quite evident (see Figure 3 and Table 7). Indeed, it is possible to state that the proposed matrix led subjects to formulate more populated tentative specifications.  
When applying the filter of \"validity\", the requirements produced by both groups undergo a considerable and statistically significant reduction (see Section 3.2). Similarly, with the additional filter of \"operationality\", although both of the groups undergo an averagely similar reduction, the differences between analysis group and control group are more apparent and still statistically significant (according to the performed Mann-Whitney test). This implies that the proposed tool failed to support the formulation of valid and operational requirements, as it performed worse than the simple checklist. However, the major negative effect can be observed for non-redundancy (see Section 3.4). Nevertheless, by analyzing the spreadsheets produced by the subjects from the analysis group, it was quite evident that the problem lay in the repetition of common requirements in different columns (representing each function). Indeed, when in the presence of a requirement representing the whole system (e.g., overall admissible size), subjects simply copied the same requirement in many different columns. Additionally, some students failed to understand the difference between wishes and demands and many repeated the same requirement on the two distinct rows. These problems can also partially explain the higher efforts perceived by the analysis group (see Section 3.6), especially in terms of physical demand (e.g., due to the unnecessary copy/paste actions).  
When it comes to the Completeness parameter, the two groups similarly focused on the Use/Benefit phase (see the radar plot in Figure 7), but the analysis group produced a more equally distributed allocation of requirements. The data are not sufficient to confirm the positive effect of the matrix in that sense, but provide a first hint for future activities devoted to a more comprehensive investigation about the observed performance.  
As for the perceived task load, Mental Demand, Time Demand, and Frustration levels are equally perceived by the subjects of both groups (although with slightly different distributions). Differently, other parameters present some differences, which highlight some possible issues for the tool. In particular, the Mann-Whitney test revealed that the differences are statistically significant (\(p\)-value \(<0.05\)) for Physical Demand and the Perceived Effort.  
Overall, mainly thanks to the higher satisfaction perceived by the analysis group (see Section 3.6), it is possible to state that this first application of the proposed matrix produced some positive effects to the subjects involved in the experiment. However, this little benefit has been overshadowed by some major problems, especially in terms of redundant requirements. Nevertheless, thanks to the identified shortcomings that led subjects to repeat formulated requirements in the matrix, useful hints for future developments can be extracted from this work, as reported in the next subsection.