The Effort Models (EMs) were designed as a set of didactic tools to highlight and discuss the role of cognitive pressure and constraints on interpreting performance, including tactics and strategies. There are EM for simultaneous with and without text, for consecutive, and for sight translation. There is also an EM for simultaneous into a sign language. The EMs show that many EOIs (Errors, Omissions and Infelicities) in interpreting performance can be traced back to overall or partial lack of availability of attentional resources, and are complemented by the idea (the Tightrope Hypothesis) that interpreters tend to work close enough to cognitive saturation (due to either effective saturation during a cognitive task or the interpreters’ not devoting all their resources to the task). The EMs are also associated with the Gravitational Model of Language Availability, which refers to the resources and time required to access linguistic information in long-term memory for speech comprehension and speech production.