Some embodiments provide a method for defining a selection of text in an unstructured document that includes a number of glyphs. The method identifies associated sets of glyphs and a reading order that specifies a flow of reading through the glyphs. The method displays the document. The method receives a start point and end point for a selection of text within the displayed document. The method defines a selection of text from the start point to the end point by using the identified sets of glyphs and intended flow of reading.