Abstract: The present invention relates to a method of ordering DNA fragments in which binary overlap information, obtained by determining whether pairs of fragments hybridize to each other, is used to build a "spanning path" across a parent DNA molecule by successively attaching cloned fragments which overlap. The relative position of the many other, non-path fragments is not essential information, but can be determined. Means for eliminating false positives and false negatives is provided. The overlap relationships between fragments may be depicted as an interval graph.