# Developing Microservice-Based Applications Using the Silvera Domain-Specific Language
## 3 Silvera
### Silvera Concrete Syntax
#### 3.3.2 Service Registry Declaration
According to the data presented in Table 18, the \(p\)-value for each question is less than the significance level (\(\alpha=0.05\)). Based on the results, we can reject the null Hypotheses (1-10) and accept the alternative Hypotheses (\(H1_{0}\)-\(H1_{10}\)). Thus, we can conclude that Silvera satisfies the following DSL quality characteristics: functional suitability, usability, reliability, productivity, extendability, and expressiveness. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Question** & **Test Statistic** & \(p\)**-Value** & **Effect Size** \\ \hline Q4: Silvera is appropriate fo MSA specification needs. & V = 153 & 0.0008 & 0.98 \\ \hline Q5: Silvera language elements are understandable. & V = 171 & 0.0006 & 1.00 \\ \hline Q6: The concepts and notation of Silvera language are & V = 171 & 0.0006 & 0.99 \\ learnable and rememberable. & V = 136 & 0.002 & 0.93 \\ \hline Q8: Silvera protects users against making errors. & V = 153 & 0.002 & 0.94 \\ \hline Q9: Silvera shortens the time needed to develop a & V = 129 & 0.001 & 0.96 \\ microservice software architectures. & V = 92 & 0.004 & 0.86 \\ \hline Q10: Silvera reduces the amount of human resource used & V = 92 & 0.004 & 0.86 \\ to develop the microservice software architectures. & V = 136 & 0.045 & 0.68 \\ \hline Q12: Each construct in Silvera is used to represent & V = 153 & 0.0008 & 0.97 \\ exactly one distinct concept in the domain. & V = 120 & 0.0007 & 0.98 \\ \hline \hline \end{tabular}
\end{table} 
Table 18: The corresponding test statistic, \(p\)-value and effect size for every question from groups _Functional suitability_, _Usability_, _Reliability_, _Productivity_, _Extendability_ and _Expressiveness_. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Question** & **0(\%)** & **25(\%)** & **50(\%)** & **75(\%)** & **100(\%)** & **Mode** & **IQR** \\ \hline Q11: Silvera provides one and only & & & & & & \\ one good way to express every concept of interest. & 2 & 3 & 4 & 5 & 5 & 4 & 1 \\ \hline Q12: Each construct in Silvera is & & & & & & & \\ used to represent exactly one distinct concept in the domain. & 3 & 4 & 4 & 4 & 5 & 4 & 0 \\ \hline Q13: Silvera does not contain conflicting elements. & 3 & 3 & 4 & 4 & 5 & 4 & 0 \\ \hline \hline \end{tabular}
\end{table} 
Table 17: _Cont._

## 6 Threats to Validity

The aim of our study was to develop a language that will accelerate the development of microservices. Although the study conducted a thorough survey, there are some threats to validity that we will discuss in this section. We distinguish between threats to construct validity, internal validity, and external validity. ### Construct Validity

Hypothesis guessingEven though participants were not aware of the hypotheses, still, they could have answered the questionnaire in a way that would favor Silvera. Before the survey, we encouraged participants to give honest answers because that is the only way for Silvera to improve, and we feel that this threat was mainly mitigated. Evaluation apprehensionA form of human tendency is to try to look better when being evaluated which confounds the outcome of the experiment [60]. The fact that the study was not anonymous could also affect the evaluation apprehension. To avoid this threat to validity we informed participants that were were not evaluating them; rather, we were evaluating Silvera. In addition, participants were not aware of other participants nor their results during the survey (each participant worked at their own home and at their own pace) to avoid any form of competition between them. In the future, we plan to enforce anonymity in contributions to further reduce evaluation apprehensions. ### Internal Validity

MaturationTo answer the questionnaire, participants first needed to familiarize themselves with Silvera either by watching the tutorials or by reading the documentation and going through examples. After that, they needed to implement a simple task. All these steps required a significant portion of their time and could lead to boredom and disinterest.