S1: Geological mapping, when properly done, demands skill and judgment. S6: Nothing is more naive than to believe that a field geologist should gather only 'facts', the interpretation of which is to be made at a later date. P: While the field work progresses he should conceive as many interpretations as are consistent with the known facts. Q: As the field work progresses and the larger geological picture begins to unfold, experience and judgment are essential if the geologist is to evaluate properly the vast number of facts gathered from thousands of outcrops. R: Such mapping requires keen observation and a knowledge of what data are significant. S: Above all, the field geologist must use the method of "working multiple hypotheses" to deduce the geological structure.