Author Dunkhase worked for 15 years as an exploration geologist and geochemist in Western United States. After that he was a professor of science education at the University of Iowa where he: coordinated the secondary and elementary science teacher education programs; directed the outreach science education graduate program for practicing teachers; was principal investigator or co- principal investigator on 5 major professional development grant projects for science teachers; and taught a field geology course in Colorado for teachers for 25 years.