"Gross approximations" refers to rough estimations or guesses that are not very accurate or precise. It means making a general or broad calculation without paying attention to small details or specific measurements. Full definition
«When we use labels like «black» or «African», they are gross approximations,» agrees Charles Rotimi of the National Human Genome Research Institute in Bethesda, Maryland, who studies the influence of culture, lifestyle and genetics on patterns of obesity, hypertension and diabetes in African Americans. (newscientist.com)
Although the models contain some well - established science, they also contain a myriad of implicit and explicit assumptions, guesses, and gross approximations — mistakes in any of which can invalidate the model outputs. (climatism.blog)