Spatial intelligence is an essential skill commonly used within various fields of science. Students with low spatial abilities frequently struggle to identify, retrieve, and apply key complex abstract information presented as multiple representations to actual three-dimensional natural materials and phenomena. Spatial ability may be considered a gatekeeper to science studies and acceptance into advanced training programs. Yet, spatial ability has been shown to be a malleable ability that can be encouraged, developed, and improved. In this action research qualitative study, the researcher/practitioner used a theoretical/conceptual framework developed from Cognitive Load Learning Theory, Cognitive-Affective Theory of Learning with Media, and Planned Behavior Learning Theory. The research participants were undergraduate entry-level chemistry students directed toward acceptance in a medical field. The course content was enriched with a variety of visualization models and representations that ranged from two-dimensional figures, interactive models, and computer simulations. The six research questions directed this research to define suitable areas of curriculum enrichment, enrichment time requirements, methods to assess participants spatial ability levels, effect of enrichment on students of all levels of spatial ability, and improvement of spatial content based on results and participants' feedback. Advance preparation of materials and presentations was required and approximately 10% of class time over a 40 hour face-to-face course was required. Initially anxious students of all spatial abilities accepted, participated, and even enjoyed most of the visual content, materials, and activities. Students with low spatial abilities gained confidence, individually developed spatial abilities, passed the course with an A or B grade, and those who had applied to advanced medical programs were accepted. Students with mid- and high-levels of spatial abilities displayed similar gains and were not negatively impacted by the enrichment. Many participants' suggestions for enrichment improvement were considered valid and incorporated into later courses. Participants overwhelmingly found visual enrichment helpful for learning chemistry. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]