Here are two ways of modelling our sample recipes. The one on this page uses the principles of relational database design. The model on page 17 uses the principles of OOA&D. They’re only examples, of course, and neither one can really be evaluated without knowing how the information will be used. A caterer who needs to scale recipes for any number of servings has very different requirements from, say, a cultural anthropologist who is primarily interested in the cultural context of the recipe, and these examples wouldn’t be particularly appropriate for either purpose. But they’ll do for our purposes.