  Requirements elicitation and requirements analysis are important practices of
Requirements Engineering. Elicitation techniques, such as interviews and
questionnaires, rely on formulating interrogative questions and asking these in
a proper order to maximize the accuracy of the information being gathered.
Information gathered during requirements elicitation then has to be
interpreted, analyzed, and validated. Requirements analysis involves analyzing
the problem and solutions spaces. In this paper, we describe a method to
formulate interrogative questions for effective requirements elicitation based
on the lexical and semantic principles of the English language interrogatives,
and propose a pattern to organize stakeholder viewpoint concerns for better
requirements analysis. This helps requirements engineer thoroughly describe
problem and solutions spaces.
  Most of the previous requirements elicitation studies included six out of the
seven English language interrogatives 'what', 'where', 'when', 'who', 'why',
and 'how' (denoted by W5H) and did not propose any order in the interrogatives.
We show that extending the set of six interrogatives with 'which' (denoted by
W6H) improves the generation and formulation of questions for requirements
elicitation and facilitates better requirements analysis via arranging
stakeholder views. We discuss the interdependencies among interrogatives (for
requirements engineer to consider while eliciting the requirements) and suggest
an order for the set of W6H interrogatives. The proposed W6H-based reusable
pattern also aids requirements engineer in organizing viewpoint concerns of
stakeholders, making this pattern an effective tool for requirements analysis.
