Residential segregation has been a prominent topic in social science since the great  sociologist  Ernest Burgess (1928) first published his landmark study on the subject more than 60 years ago.  For almost as long, sociologists have argued about how to  measure it.  The debate has  ebbed and flowed, and for a time the issue seemed settled.  In 1955, Otis Dudley Duncan and  Beverly Duncan published a widely -cited article demonstrating that  there was little information  contained in any of the then-prevailing indice s that was not already  captured by the index of  dissimilarity.  For 20 years thereafter, this measure was employed as the standard index of  residential segregation.