  Context: Architecture Tactics (ATs) are architectural building blocks that
provide general architectural solutions for addressing Quality Attributes (QAs)
issues. Mining and analyzing QA-AT knowledge can help the software architecture
community better understand architecture design. However, manually capturing
and mining this knowledge is labor-intensive and difficult. Objective: Using
Stack Overflow (SO) as our source, our main goals are to effectively mine such
knowledge; and to have some sense of how developers use ATs with respect to QA
concerns from related discussions. Methods: We applied a semi-automatic
dictionary-based mining approach to extract the QA-AT posts in SO. With the
mined QA-AT posts, we identified the relationships between ATs and QAs.
Results: Our approach allow us to mine QA-AT knowledge effectively with an
F-measure of 0.865 and Performance of 82.2%. Using this mining approach, we are
able to discover architectural synonyms of QAs and ATs used by designers, from
which we discover how developers apply ATs to address quality requirements.
Conclusions: We make two contributions in this work: First, we demonstrated a
semi-automatic approach to mine ATs and QAs from SO posts; Second, we
identified little-known design relationships between QAs and ATs and grouped
architectural design considerations to aid architects make architecture tactics
design decisions.
