We have a general tendency to rush readings on a display than on paper. The verification of the rush tendency is our first focus. We assume that readers may feel impatient on a display because it is generally difficult for them to know in what position they are in a document; on a display. In this study, we have quantified the rashness of reading work on a display. We have also investigated essential causes of the rashness on a display. We have measured time consumption for reading a certain length of document in the following three displaying conditions: 1) A whole page show with page partitions, 2) Partial show of a page with page partitions, 3) Partial show of a page with vague page partitions. We have also measured performances of the readers to questionnaires asking contents of the document. The shortest reading time and resulting lowest correct answer rate were shown by the reading condition (3) with partial show of a page besides with vague page partitions. We suppose the subjects hurried in the reading condition where they were not sure how much volume they were going to read and that their correct answer rate naturally decreased as a result of shorter reading time.