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Decision Trees

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Decision Trees    
    
     The reaction to this gloomy follow-up report, however, was predictable. The Israelites were in virtual panic; when the dust had settled, they refused to move into the Promised Land, and it fell to Caleb and Joshua, 39 years later, to lead the next generation into the land these people had refused to seize.
    
Deterministic vs. Probabilistic Trees   
    
     Managers are faced with both repetitive and non-repetitive situations. The repetitive ones are generally susceptible to "standard operating procedures" which both resolve specific recurring problems and contribute to the development of behavior patterns in an organization. It is the non-repetitive situation that causes problems-and it was such a situation that Moses faced. Non-repetitive situations involve new and significant incidents, changes in policies or procedures affecting probable outcomes, and usually emphasize the fact that no body of past experience is directly or comprehensively applicable. Stereotyped problem-solving procedures are recognizably inappropriate; the new situation is often ill-structured, and reliable information regarding it is often scarce. In such cases the conventional problem-solving approach (curing symptoms with readily available expedients) usually results in a new and completely unexpected symptom arising. It is in such situations that a workable model of the entire problem should be constructed and then manipulated as a substitute for costly trial-and-error experimentation with the actual resources. These, in other words, are cases for the decision tree.
    
     A deterministic use of the decision tree as a problem-solving device can be effectively demonstrated by examining Moses' tasking of the spies. They were to discover a series of states of affairs-states that either existed or did loot-with no probability associated. (See Chart 3 again.)
    
     In this particular tree I included an assumed instruction to return to camp if the initial observation from the mountaintop showed the land to be worthless. I also inserted a key decision the Israelites had to face--could the resident peoples in the Promised Land be overcome?-and a suggestion of the conversion of the tree into a similar device to help in the probabilistic assessment of an invasion's success.
    
     As I mentioned earlier, another and quite powerful use of the decision tree is as a probabilistic tool in the decision process. One key question facing Moses as the leader of his people was whether they had sufficient unity and cohesiveness as a nation to accomplish the difficult task of invading occupied territory by force of arms to carry out "the will of the Lord." In retrospect, the decision that Moses was compelled to make in regard to that unity can be depicted as a probabilistic decision tree. (See Chart 4.)
    
     The branches of this tree are easy to construct after the fact, and they again enable the student of the management of non-repetitive situations to obtain a clear perspective of the factors and possible consequences of alternate courses of action.
    
     The development of such a tree before the fact is much more desirable, but correspondingly more difficult. There are few cut and dried means of assuring the inclusion of all alternatives, and the best advice seems to be to
    
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Posted: May 08, 2007 08:43 AM
Last Updated: May 08, 2007 08:43 AM