# An Activity Theory-Based Approach for Context Analysis, Design and Evolution
## 4 Testing Ideas through Experimentation
### Measurement Factors and Rating Scales
_[C] Collaboration:_ A key feature to evaluate in the applied approach is how it facilitates teamwork between all those involved, using elements such as the definition of a common vision between users/stakeholders and the design/development team. This also includes the capacity to register and track the context model produced during the entire development process, i.e., its resources to delimit, document, manage changes and control the context modeled, etc. _[D] Traceability:_ This factor evaluates if the applied approach can generate useful artifacts for communication and documentation (diagrams, schemes, reports, etc.). This documentation is intended to be accurate, complete, consistent, and above all, understandable for users, stakeholders and design and development teams, helping to ensure fluid communication. In Table 3, we show the measurement factors described for the experiment and the questions that motivate its application to the approaches selected for evaluation. The four factors indicated in Table 3 are further divided into the sub-items in Table 4. These sub-items allow for the structuring of the properties that we intend to identify and evaluate in each of the selected approaches. Thus, comparable factors can be obtained. \begin{table}
\begin{tabular}{l l l} \hline \hline
**Factor** & **Sub-Item** & **Related with** \\ \hline \multirow{6}{*}{**[A]**} & **A.1:** & Acquisition of inputs and outputs for the analyzed context \\  & & Identification of the human actors/actors involved and their roles in the situation under study \\  & & **A.3:** & Addressing of potential restrictions, conflicts, incidents, or risks in the modeled context \\  & & **B.1:** & Effective visualization of potential unwanted events \\  & & **B.2:** & Defines a clear context scope \\  & & **B.3:** & Specifies contexts models clearly to human agents (users, stakeholders, design and development team) \\  & & **B.4:** & Use a standard mechanism to express the modeled context \\  & & **C.1:** & Change management and context problems can be solved efficiently \\  & & **C.2:** & The collaboration and interaction between human agents (users, stakeholders, design and development team) is fluid and standard \\  & & **C.3:** & The features and functional attributes of the design for the context-aware \\  & & **C.4:** & There is an evolution and feedback of knowledge that refine the \\  & & **D.1:** & The documentation generated is consistent with the development and \\  & & **D.2:** & quickly become familiar with the documents, diagrams, and schemes \\  & & & produced and communicate discrepancies, errors, or incidents using them \\  & & **D.3:** & The design and development team uses and understands the \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Sub-Items evaluated for each factor. Regarding the rating scales, it was considered that, in a sample of individuals (evaluators), each one will have a different perspective about each factor (Table 3) and its sub-items (Table 4). Likewise, the evaluator's criteria will be used to evaluate and weigh the approach reviewed (activity theory-based approach or UML-based approach). As the data collected should avoid being biased, a rating scale, within a sample of variable size, will reduce or eliminate the margin of error in the data obtained. Consequently, a model based on a Likert scale [53] was considered as the most appropriate option. The scale used in this work is summarized in Table 5.  
To make estimates, each sub-item in Table 4 was weighted based on the scale values in Table 5. The average of the sum for each sub-item evaluated establishes the value total obtained by each factor of Table 3. This procedure is expressed by the following formula:  
\[\overline{x}=\frac{\sum_{i=1}^{n}x_{i}}{n}\]  
where \(\overline{x}\): It is the value of a measurement factor according to Table 3, based on the average of each sub-item \(x_{i}\) that corresponds to that factor, \(x_{i}\): Corresponds to the value of each sub-item in a measuring factor.