It is on ergonomics and cognitive representations, and in the first part of the paper the 2 authors' present a succinct explication on a broader mental model literature review. The clarity of their conclusions is very informative to someone who is from a design discipline. I will post later on how their paper has helped me process my understanding of the literature I have read. We are approaching the literature from the requirements of two different discipline inquiries, but notwithstanding the obvious deviations in the literature some of their sources suggest further HCI literature to read. It is clear that S.J. Payne is an author I still need to read. I haven't yet sourced any of his writing despite being cited within the other literature. His Russian doll analogy of the theoretical strata of a mental model, I am sure, will be very useful to me as a tool to understand Johnson-Laird's definition.
What I have found extremely useful in clarifying the difference between mental and cognitive models is contained in a comparison table at the end of the paper. I will summarize it here:
Mental Models are dynamic constructs within a person's working memory (WM) during the performance of a task. This means that a mental model is task-specific, informed by external representations and reasoning about the actions needing to be performed. Therefore a mental model is informed by the conceptual model, and not to be confused with it.
Conceptual Models are a construct of a person's long-term memory (LTM) and are non-task specific. This makes them static during a task as the underpinning reasoning associated with a conceptual model is informed by existing knowledge of a system, a pre-existing experience that aids their representation on how that system behaves. Like mental models they are also informed by external representations, but conceptual models inform a person to dynamically construct a mental model or image in order to use the system in question.
Now that I have a clearer understanding between the terms I can return and re-evaluate my last 4-5 posts.
Reference
RICHARDSON, M. and BALL, L.J. (2009) Internal Representations, External Representations and Ergonomics: Towards a Theoretical Integration. Theoretical Issues in Ergonomics Science. 10(4), pp 335–376