document: Finding partial orders from unordered 0-1 data In applications such as paleontology and medical genetics the 0-1 data has an underlying unknown order ( the ages of the fossil sites , the locations of markers in the genome ) . The order might be total or partial : for example , two sites in different parts of the globe might be ecologically incomparable , or the ordering of certain markers might be different in different subgroups of the data . We consider the following problem . Given a table over a set of 0-1 variables , find a partial order for the rows minimizing a score function and being as specific as possible . The score function can be , e.g. , the number of changes from 1 to 0 in a column ( for paleontology ) or the likelihood of the marker sequence ( for genomic data ) . Our solution for this task first constructs small totally ordered fragments of the partial order , then finds good orientations for the fragments , and finally uses a simple and efficient heuristic method for finding a partial order that corresponds well with the collection of fragments . We describe the method , discuss its properties , and give empirical results on paleontological data demonstrating the usefulness of the method . In the application the use of the method highlighted some previously unknown properties of the data and pointed out probable errors in the data .
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