However, because appropriate tools were not available, Hogan could only consider a limited number of events, and the timing of event was not taken into account. Person A who finished school, got a job immediately, and got married within a year would be considered to belong to the same sequence-type as B who took a year to find his first job after finishing school, and stayed unmarried for the next ten years. OMA is a family of procedures that takes into account the full complexity of sequence data. The objective is to identify a typology of sequences empirically. It was developed by, among others, molecular biologists who study protein or DNA sequences.
Biologists often wish to find out how different a particular DNA sequence is from other sequences.
Knowing this will help them reconstruct the evolutionary tree. The core of OMA is a two-step procedure. First, given a set of sequences, find the distance between every pair of sequences though an iterative minimisation procedure. This will give the researcher a distance matrix for all the sequences. Secondly, apply clustering or cognate procedures to the distance matrix to ascertain if the sequences fall into distinct types.