Discussion
This paper assesses diversity and validity in PMAR based on a content analysis of 375 papers published over four decades. We argue that a diverse set of research methods and theories, along with the consideration of validity, constitute important prerequisites for the accumulation of knowledge on MA practice (e.g., Bonner et al., 2012; Edwards et al., 2013; Hoque et al., 2013; Luft and Shields, 2002; Merchant et al., 2003). Our analysis relies on the propositions that the diversity of research approaches and the validity of inferences increase as PMAR moves forward from the description of MA practice towards its explanation. However, in light of recent debates on the state of MA research, we consider that institutional pressures may put such progress into perspective (e.g., Birnberg, 2009; Merchant, 2010).
