STELLA (programming language)

[3][4][5] While working at the Massachusetts Institute of Technology in the 1960s, Jay Wright Forrester developed the earliest understanding of system dynamics which he argued could only be understood using models.

[4][8][10] Within that paper, Richmond mused on the study of system dynamics: "If this stuff really is so great, then why hasn't the field 'taken off'?

[8] He quoted a 1994 paper in which Richmond described STELLA as "quite unique, quite powerful, and quite broadly useful as a way of thinking and or learning.

DYNAMO explicitly defined "stocks" (reservoirs) and "flows" (inputs and outputs) as key variables in a system, a vocabulary that STELLA shares.

[6] Richmond derisively viewed most education as "assimilating content" and proposed systems thinking as a remedy to this.

[28] A 2010 study of the efficacy of project-based learning upon a watershed-modeling project undertaken by 72 middle schoolers found that the addition of a STELLA modeling component in the project improved overall comprehension of the material over traditional methods, especially among female students who outperformed their male counterparts with the addition of STELLA.

Among other projects, researchers have used STELLA to apply Hubbert peak theory to the Chinese coal supply,[30] to model atrazine dynamics within agricultural lands,[31] and to simulate the interactions between marine macroinvertebrates.

[5] In a 1987 review of the program in BioScience, Robert Costanza wrote that "STELLA is a solid program–well planned and executed–that breaks new ground.

A diagram with a blue rectangle ("Cat population") being fed by blue arrows ("Cat births" and "Cat deaths"). Pink arrows feed the blue arrows from "Cat birth rate" and "Cat death rate" circles.
A simple STELLA model of a cat population; stocks are represented as rectangles, flows as pipes to/from the stock, converters as the circles, and connectors as the curved lines with arrows. [ 12 ]
A STELLA model from a paper on carbon impacts in forest biomass [ 21 ]