Fourth, there are several methodological difficulties regarding the trim - and - fill method. (link.springer.com)
We do not know if the trend toward simpler procedures is actually in operation, owing to methodological difficulties of measuring cross-nationally the ease of constitutional amendment. (slaw.ca)
«Psychologists have been building personality profiles manually for years; however, there are serious methodological difficulties associated with this practice.» (sciencedaily.com)