# An Activity Theory-Based Approach for Context Analysis, Design and Evolution
## 4 Testing Ideas through Experimentation
### Measurement Factors and Rating Scales  
To provide an objective comparison between an activity theory-based approach vs. an UML-based approach, four factors of interest were measured. These factors are the result of several instruments designed to understand the complexity associated with the process of acquisition, analysis, design, and modeling of contexts. Some relevant questions in this regard are, for instance, _what should be measured? how should it be measured_? and, _how should the measurements be compared_? The development of these questions entails an underlying methodological procedure that led to the design of the factors presented. Initially, the problem of finding what should be measured, particularly in complex environments, such as context-aware software development, can be an unmanageable task if it starts from theoretical methods or from general metrics, such as cost and effort estimation, lines of code (LOC), code complexity, etc. For this paper, a more pragmatic approach was chosen, where twelve specialists (researchers, designers, and developers) were interviewed about which aspects they considered to be the ideal for this type of development. Thus, a survey was carried out to collect some data from these specialists. The results and answers, according to the criteria and experience of those interviewed, converged in several topics such as the _ability to easily interpret diagrams_, _the richness of details in design schemas_, the _capacity to perform collaborative tasks within the project_, the _possibility of easily introducing changes and outlining solutions to conflicting elements in the project_, among other aspects. The opinions that pointed towards a regular observable pattern were synthesized in the form of four factors (shown in Table 3). Other criteria, subordinated to the previous general opinions, were organized as sub-items (shown in Table 4). \begin{table}
\begin{tabular}{l l} \hline \hline
**Factor** & **Questions to Research/Reply** \\ \hline
**[A]: Context Richness** & Does the approach represent the context and conceptualize an overview of the problem? \\  & Does the approach induce the elicitation of the context? \\
**[B]: Understandability** & Can the approaching express, describe, and be understood by human agents (users, stakeholders, design and development team)? \\
**[C]: Collaboration** & Does the approach allow us to build a chronology and follow-up of the process? \\  & Is it possible through the approach to managing changes in context? \\  & Does the approach produce documentation? \\
**[D]: Traceability** & What kind of documents does it produce? \\  & Is the documentation produced sufficiently communicative, comprehensive, and descriptive? \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Measurement factors to be evaluated. In consequence, this procedure provided the factors that will be used in this study for comparing an activity theory-based approach with a UML-based approach. The details of these factors, and how they were used in this study, are described as follows:  
_[A] Context Richness:_ The approach evaluated must allow for a rich representation of the context, providing enough information to model some essential properties such as, for instance, the profile of the human actors/agents involved, the relationship between the processes performed, and the expected results and objectives, etc. _[B] Understandability:_ This factor evaluates if the applied approach offers mechanisms that gradually lead designers/developers to an efficient elicitation of the intentions in play within a context (what should be done). Also, this topic attempts to measure features that facilitate the statement of purposes (how it should be done) using consistent expressions to describe the functionality and/or rules that allow for the defining of the context and the ability to rationalize several possible scenarios, mainly those unwanted, etc.