This chapter discusses the idea of constructing mental models; they can be used from the early stages of the process onwards to outline the characteristics of future users and to use this information as an aid in translation. It also explains three tools which can be used in the construction of mental models: intratextual reader positions, audience design and personas. The chapter explores mental models by discussing those reader images which can be discovered in the text itself. These images are called as intratextual reader positions. The implied reader is a rather well-known instance of these in translation studies, while in technical communication we also find the concept of reader as a rhetorical participant. Whereas intratextual reader positions are a text-based analysis tool, audience design focuses on the context of reception. Audience design could be described as recipient-oriented communication design. Personas are used as an aid in designing a variety of products and services.