Sentence:  The reason for this concentration is to attempt to alleviate the problems of fragmentation which usually accompany the study of retailing, particularly at the end of the early period, and has so often happened in the past, to curtail the temptation to <WSD>'cherry-pick</WSD>' the best evidence from a wide, but not necessarily related, area. 
Meaning of the word marked with <WSD> tags:  To select only evidence which supports an argument, and reject or ignore contradictory evidence.