The two important factors in determining how to design an algorithm are the accuracy of the result and the efficiency of the processing. Definitive algorithms perform tasks that have a definite answer and a best method for processing. An example is searching for a word in a list. Depending on the size of the list, certain search algorithms are more efficient then others. Definitive algorithms are typically of interest to only computer scientist.
Subjective algorithms are more interesting for business purposes.
Subjective algorithms are used heavily in social sciences, economics, business and financial forecasting, etc. The best-known examples of subjective algorithms on the Internet are those used by public search engines.