This paper reports on an investigation of two inter-related but different matters, one of interest to science education researchers and teachers in general, and the other to those teaching about evolution. The first was motivated by the dilemma facing teachers who want to diagnose learners' prior knowledge before teaching and are concerned about the teaching time needed to identify existing ideas in a valid way. The paper reports on four benefits of adding a confidence scale to a true-false quiz which is quick and easy to use for diagnostic purposes. The second aspect of the study was motivated by the problems experienced by many religious students when they face the challenge of learning about evolution.
The nature and extent of prior ideas of 32 grade 12 students at a religious Jewish school in South Africa are identified and discussed within a framework of border-crossing, as religious students learning about evolution might be expected to have difficulties functioning in a science context which they might perceive to conflict with their religious world-view. Although the frequency of unscientific ideas about mechanisms of evolution was high, as expected from students who had not been taught the topic, erroneous ideas typically associated with understanding the nature of science, as well as some associated with religious beliefs, were unexpectedly low.