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The research purpose was to explain the user's influence on energy consumption with cooking systems using electricity. This research was conducted in two phases. The research objective of Phase I was to determine if relationships exist that explain the user's influence (i.e., user characteristics--knowledge, experience, practices, and user interaction--and appliance operating time) on the energy consumption of cooking systems using electricity. The ultimate aim of this research, the outcome of Phase II, was to identify categories of cooking style that explain the user's influence (i.e., user characteristics and appliance operating time) on energy consumption of cooking systems using electricity. The data used to answer the research question consisted of video tapes of consumers preparing the research menu, a survey, and data recorded on a data collection sheet by the researcher (i.e., watthour consumption). Simultaneous triangulation was used to answer the research questions. Phase I determined that energy consumption was correlated with knowledge, user interaction, practices, appliance operating time, cooking system interaction, goodness-of-fit, information, behavior, the user, and statistical interaction between the cooking system and goodness-of-fit. Independent variables explained 38.6% of the variation in energy consumption. However, when only the variables under the user's control were included in the regression model, just 25% of the variation in energy consumption was explained. Phase II determined the three most important factors that distinguish the five cooking style categories based on user characteristics (i.e., patient style, average style, uninformed style, hurried style, and hurried style with no control) were: (a) percentage of the sample that left the heat source on after cooking, (b) percentage of the sample that did not match the diameter of the heat source and the diameter of the cookware when using high heat, and (c) percentage of the sample that fried using high heat. Additional variables that differed among categories were: reusing hot elements, use of retained heat, and use of medium heat settings. In summary, important factors in explaining variations in energy consumption include: inherent characteristics of the cooking system, user's knowledge, highest heat setting selected and matching the diameter of the heat source with the cookware diameter, leaving the heat source on after cooking, and selecting highest heat setting when frying. Three categories of consumers cooking style were developed (i.e., low, average, high energy consumption) to summarize the data. The highest heat setting selected and leaving the heat source on after cooking was completed were factors that distinguished consumers among the three categories. Ph. D.

A laboratory experiment was performed to investigate the interaction between container material and energy source. The energy sources used include: conventional electric coil, gas flame, induction, solid element, and electric resistance coil under glass-ceramic. The container materials investigated include: thin gauge aluminum, heavy gauge aluminum, glass-ceramic, thin gauge porcelain-on-steel, and heavy gauge stainless steel with thick aluminum heat core. Crepes were prepared to determine the browning pattern for each cooking system (combination of energy source and container material). Water was used as a test medium for both speed of heating and retained heat tests. Duncan Multiple Range Tests were performed to determine significant differences between systems, and a General Linear Models Procedure was used to assess the contribution made by each variable on variances between systems. When speed of heating, and retained heat are desired, the important variable was the cooktop. The induction, gas flame, and conventional electric coil boiled water more quickly, and the solid element and the electric resistance coil under glass-ceramic retained the most heat. When even browning is desired, the choice of cookware is important. Heavy gauge aluminum and heavy gauge stainless steel with a thick aluminum heat core produced the most even browning. Systems that performed all tests well include the conventional electric coil paired with heavy gauge aluminum or heavy gauge stainless steel with thick aluminum heat core cookware. Master of Science

Effects of container geometry and material on microwave cooking performance, as measured by evenness of cooking, firmness, and moisture content were compared. Three food items were heated in round, tube, loaf, and square containers made of clear glass, amber glass, thermoset polyester, and polysulfone. Unflavored gelatin, custard, and cakes were prepared three times in each of the 13 microwave containers. Evenness of cooking was determined by comparing meltdown and temperature in gelatin, temperature and separation/uncooked portions in custard, and index to volume in cakes. Firmness was measured in custard while moisture content was determined in cakes. In analysis of the data, ANOVA and Duncan's multiple range test were performed. Significant differences were found between shapes as food items heated more evenly in tube and round containers than in square containers. Food quality was affected more by shape than by material. Foods prepared in the, plastic materials were more evenly heated than in the glass materials. Statistically, shape and material interacted with each other for three measures of microwave appliance performance temperatures and separation/uncooked portions of custards, and index to volume in cakes. The interaction of shape and material was greater as the heating time increased. Master of Science