▁conduct ▁of ▁members ▁of ▁the ▁profession , ▁and ▁some ▁degree ▁of ▁dem arc ation ▁of ▁the ▁qualified ▁from ▁un qual ified ▁am ateurs ▁( that ▁is , ▁professional ▁cert ification ). ▁It ▁is ▁also ▁likely ▁to ▁create ▁" occup ational ▁closure ", ▁closing ▁the ▁profession ▁to ▁entry ▁from ▁out s iders , ▁am ateurs ▁and ▁the ▁un qual ified . ▁ ▁Occ up ations ▁not ▁fully ▁professional ized ▁are ▁sometimes ▁called ▁sem ip ro f essions . ▁Crit ique ▁of ▁professional ization ▁views ▁over ze alous ▁versions ▁driven ▁by ▁per verse ▁in cent ives ▁( ess entially , ▁a ▁modern ▁analog ue ▁of ▁the ▁negative ▁aspects ▁of ▁gu ild s ) ▁as ▁a ▁form ▁of ▁cred ential ism . ▁ ▁Process ▁The ▁process ▁of ▁professional ization ▁creates ▁" a ▁hier arch ical ▁divide ▁between ▁the ▁knowledge - author ities ▁in ▁the ▁prof essions ▁and ▁a ▁de fer ential ▁citiz en ry ." ▁This ▁dem arc ation ▁is ▁often ▁term ed ▁" occup ational ▁closure ", ▁as ▁it ▁means ▁that ▁the ▁profession ▁then ▁becomes ▁closed ▁to ▁entry ▁from ▁out s iders , ▁am ateurs ▁and ▁the ▁un qual ified : ▁a ▁strat ified ▁occupation ▁" defined ▁by ▁professional ▁dem arc ation ▁and ▁grade ." ▁The ▁origin ▁of ▁this ▁process ▁is ▁said ▁to ▁have ▁been ▁with ▁gu ild s ▁during ▁the ▁Middle ▁A ges , ▁when ▁they ▁fought ▁for ▁exclusive ▁rights ▁to ▁practice ▁their ▁tr ades ▁as ▁jour ne ymen , ▁and ▁to ▁eng age ▁un pa id ▁app rent ices . ▁It ▁has ▁also