This dissertation in practice utilized a sequential mixed methods research design to investigate the performance or exclusion of instructional design activities commonly prescribed by instructional design models during a typical instructional design project. The purpose of this study was to compare the performance of instructional design activities by practicing instructional designers with the performance of an experienced instructional designer to determine if instructional design models are being used to guide the practice of instructional design. In this study, quantitative data was collected from a sample of 224 instructional designers to determine the activities routinely performed and excluded from typical projects. Qualitative data was collected from a single case study of an instructional design project to assess whether or not the performance or exclusion of the same instructional design activities were identified in the work of an experienced instructional designer. Analysis of the data revealed the activities that are not routinely performed by instructional designers, reasons for the exclusion of activities, and possible factors for the decisions to exclude activities. The findings of this study indicate instructional designers may be sacrificing the quality and effectiveness of instruction in an attempt to increase the pace and reduce the cost of the instructional design process. The study concluded that instructional designers are not following the prescriptions of instructional design models during the practice of instructional design by routinely eliminating the fundamental activities involving the development of learner assessments, the performance of formative evaluations during the instructional design process, and summative evaluations after the implementation of the instruction
