According to related management literatures, the concept of 
organizational commitment was not much acknowledged to a great extent 
until the pedagogy of organizational and management science had entered the 
Human Relations era. A management theorist, Mary Parker Follet, is believed 
to be the first to mention individuals loyalty to the organization. (Robbins,1990 
: 89) Chester I. Barnard came closer to some current definitions on organizational 
commitment when he called for an integration of employees purposes and 
organizations goals. Nonetheless, among the earlier scholars who mentioned the exact word of commitment, Philip Selznick, in discussing cooperative 
systems within the informal structure, emphasizes ties of friendship, class 
royalty, power cliques, and external commitment. (Selznick, 1945 : 26) Despite
the diverse, overwhelming classification schemes in its definitions, there is a 
consensus that recognizes commitment as a multi-dimensional construct 
primarily involve the strength of individuals identification with and involvement
in a particular organization. (Meyer and Allen, 1997) According to Porter et al,
organizational commitment is defined as: