Students completing a time calculation exercise identified the International Date Line (IDL) as a conceptual source of confusion and poor performance. From the early 1950s to the present, various geography textbooks have promulgated misstatements involving the occurrence of midnight at the IDL. This condition's persistence and ubiquity manifests a…

The accuracy of data collected by Dutch geography students in a field study of commercial activities in a French city was monitored with data available from official lists. The causes of error, both in student work and official sources, and some lessons for future field work are examined. (Author/IS)