The present book proposes a new descriptive model, the so called "Ideation Model" (IM), of the design process from a dual cognitive-engineering perspective, partly, based on existing models from both fields and previous work performed. The model, addresses the issue of modeling the ideation or the front-end phase of the, engineering design/product development process, representing the interface of cognitive psychology and engineering design. Three domains - inspiration, decomposition and integration - and three spaces - problem-space, idea-space and, concept-space are considered as elements of the model. The iterative flow of the engineering design process passes through these domains in a semi-controlled way, through a sequence of specialization and generalization process loops in - and, between the spaces. Empirical examinations - prescriptive and descriptive - to the IM, are performed, using both novice and expert designers belonging to the academia. The empirical work indicates these designers worked in a manner largely consistent with the model.