This research supports the choice of a Design and Development Research approach for the creation and validation of ID methods, thus providing a theoretically-grounded and pedagogically-inclusive method for designing reusable pedagogical scenarios. It also presents a framework for articulating a generic instructional design theory with a coherent instructional design method, and hence, it contributes to augmenting the instructional design knowledge base. This dissertation presents a research divided into four main phases of development and validation. The first phase grounds the research in a theory of instructional design that aligns it with other related design disciplines, and decomposes the design problem into layers of artifact functionalities. This theory corresponds to software-engineering-infused instructional design methods also known as courseware engineering.The second phase explores ways to integrate an educational modeling language within an instructional design method for enabling the representation of pedagogical scenarios of computational facture. To reflect and experiment on this issue, we have chosen to study the MISA instructional design method developed at the LICEF research center and the IMS LD specification. The third phase presents an initial developmental solution, which is tested in a case study. We studied the introduction, into the MISA method, of a new technique supporting the design of a MISA pedagogical scenario according to IMS LD constraints. The aim was to test an 'economic' solution that would not require further modifications to the MISA method. We therefore conducted a case study where a technique for the representation of a conformed to IMS LD pedagogical scenario was applied to the transposition of a MISA pedagogical scenario by an expert instructional designer. The fourth and final phase exends the development and validation of a solution by way of a two-round Delphi method. We requested the participation of four experts. This developmental step included a selection and introduction of minor modifications of a set of MISA documentation elements identified as crucial for the design of IMS LD compliant pedagogical scenario. The Delphi enabled agreement on an adapted version of the MISA method that fulfills the design purpose. The final outcome of the design process is a pedagogical scenario with all the information required to run an IMS LD-like pedagogical scenario organized in a semi-formal manner and capable of translation into a structured markup language for running in a compliant learning management system. In this sense, the pedagogical scenario results in a document that can be understood as an intermediate state between a blueprint and an executable UoL.