The phrase "a three stage model" is correct and usable in written English.
You can use it when describing a model that consists of three distinct stages or phases in a process or system.
Example: "The research presents a three stage model for understanding consumer behavior."
Alternatives: "a three-step framework" or "a triadic model".
We first develop a three stage model for understanding chirp excitation in NMR.
Yang and Tang have discussed these difficulties of requirement elicitation in web-based services and have presented a three stage model of requirement elicitation: When we come to web-based services, users are generally diverse.
We recently published a three stage model for the peopling of the Americas [1].
Our proposal for a three stage model for the peopling of the Americas remains essentially unchanged despite the modifications to the skyline plot described above.
We fitted three standard models to the data and the phylogeny, known as the "equal", "symmetrical", and "all different" rate models and added a custom model assuming a three stage model of evolution.
We found that diagnostic reasoning can be split into a three stage model: initiation of diagnostic hypotheses; refinement of the diagnostic hypotheses; and defining the final diagnosis (fig 1).
The objective of this paper was to develop a two stage model for moisture-induced deformations in expansive soils.
In this article we describe a six stage model for the design of evidence-based intercultural education and training programs.
We present a seven stage model of ice sheet evolution, from initiation to demise, in the form of palaeo-geographic maps.
The test rig studied in this paper is called Low Emission Stirred Swirl (LESS) combustor, which is a two stage model combustor, fueled with liquid RP-3 kerosene and designed by Beijing University of Aeronautics and Astronautics (BUAA).
