“…Quantitative studies use researcher-developed or previously validated questionnaires or inventories (e.g., Kwan & Walker, 2008;Sutter, 1996) to obtain data from 100-400 assistant principals working across countries (e.g., Kwan, 2009a), states (e.g., Cranston, Tromans, & Reugebrink, 2004), or large cities (e.g., Garrett &McGeachie, 1999). Smallerscale qualitative studies also have been conducted, employing individual and focus-group interviews, open-ended questionnaires, case studies, observations, and document analysis.…”