# Linguistic Patterns and Linguistic Styles for Requirements Specification: Focus on Data Entities
## 6 Evaluation Based on a Pilot User Session
### Questionnaire Analysis  
As introduced above the questionnaire involves several questions grouped into four dimensions of analysis. First, after the questions related to the general characterization of each participant, the first question that requires the participants to rate was Q3:  
**Q3:**_How do you rate the proposed linguistic patterns (Data Entities, Data Attribute, Data Constraints, Cluster of Data Entities)?_  
Responses to this question revealed good to very good grades, as summarized in Table 4: Data Constraints patterns were rated slightly below 4 (i.e., 3.74), while the others had the average ratings above or equal 4, namely: the average rating was 4.58 for DataEntity, 4.53 for DataEntityCluster, and 4.0 for DataAttribute patterns in the 5-Likert scale (in which 1 is Very Low and 5-Very High). We may also conclude that the more difficult to understand and to apply patterns (i.e., DataConstraint and DataAttribute patterns) were rated slightly lower than the others. Second, the questionnaire included 4 questions that asked participants to rank different qualities (i.e., simplicity, expressiveness, readability, and completeness) of the discussed linguistic patterns:  
**Q5:**_How do you rate the CNL-A linguistic style, in what concerns..._? **Q6:**_How do you rate the CNL-B linguistic style, in what concerns..._? **Q7:**_How do you rate the RSL linguistic style, in what concerns..._? \begin{table}
\begin{tabular}{l c} \hline \hline
**Linguistic Patterns** & **Result** \\ \hline Data Entity (lp1) & 4.58 \\ DataAttribute... (lp2) & 4.00 \\ Data Constraint (lp3) & 3.74 \\ Cluster of Data Entities (lp4) & 4.53 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: How do participants rate the proposed linguistic patterns (values in a 1–5 scale)? **Q8:**_Which notation is most appropriate for describing the proposed patterns?_  
Concerning simplicity of CNL-A, CNL-B, and RSL (see Table 5 and Figure 8), participants gave the highest score to CNL-A notation (the average score was 4.47), while the lowest score was given to RSL linguistic style (3.53). Additionally, CNL-B had the average score between these two scores (exactly 4). When expressiveness is considered, RSL was the best rated one, with a score of 4.21. CNL-A and CNL-B have similar average ratings with regards to readability (4.32), while RSL is rated as the best one when completeness is concerned (4.47). According to the survey, ten (52.6%) participants responded that CNL-B was the most appropriate notation for describing the proposed patterns. This was followed by six participants (31.6%) that voted for CNL-A, and three (15.8%) voted for RSL. This result is a little surprising, considering that the average grades of all three notations are very close, but also understandable since RSL sentences are less simple and easy to read than the equivalents in CNL-A or CNL-B. Third, the questionnaire included two open questions:  
**Q9:**_According to the description of \"BillingSystem\" (See details in Appendix A) please specify the remaining entities (including the respective attributes, constraints, etc. ), namely for \"Invoice\", \"InvoiceLine\" and \"Customer\", using your preferred notation. In particular, you may choose to use CNL-A, CNL-B, RSL, or even other textual notation._  
**Q10:**_Please, justify your decision regarding the previous question._  
Not all participants specified the remaining entities described in the case study, but most did (15 of them). When performing a careful analysis of the submitted specifications, we noticed that participants mostly used CNL-B and RSL linguistic styles. All responses  
Figure 8: Bar-chart on how participants rate the linguistic styles (values in a 1–5 scale). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Styles** & **Simplicity** & **Expressiveness** & **Readability** & **Completeness** \\ \hline CNL-A & 4.47 & 3.58 & 4.32 & 3.54 \\ CNL-B & 4.00 & 4.05 & 4.32 & 3.95 \\ RSL & 3.53 & 4.21 & 3.89 & 4.47 \\ \hline \hline \end{tabular}
\end{table}