Typically models are developed by researchers for a specific purpose—-they seek the best way to understand ‘x’—and often for a particular problem.A useful model often has broader application than the unique, the single question being asked, and is adopted by others who find its parameters fit the problems they wish to study. A few are so generally accepted and so adaptable—the gravity model, for example—that they are folded into the address of studies of a range of problems.

Dear Tom koch,

Thank you, for your valuable explanation.

Well explained

A model is a schematic description or representation of something, especially a phenomenon or system, used to underscore important properties and/or dynamics in a process. It stands to reason that the likely end-user of a model will be the researcher(s) who developed it to shed light on a particular issue or problem; that said, others may find value in the model if it holds sufficient explanatory power, conceivably also in different fields of scientific endeavor.

I want to express my humble opinion to Dr. Muhammad Anwar Iqbal on his interesting question.

Before talking about my personal experience related to the mathematical model, I would like to appreciate prof. Tom Koch and prof. Olivier Serrat for their s deeply thoughts that are reflected in their answers.

In 2007, the university refused my proposal for my desertion until I have designed and wrote the mathematical model. The chair of the committee considered the mathematical model as a core request. Writing that model has cost me an extra year of hard work.

Now, I believe that this model is an integral aspect of linking the conceptual framework or theoretical framework to practice. Without this model, bridging the gap between theory and practice is very difficult.

It is unusual, in my experience, to receive praise for an answer to questions in this forum. So thanks to all those who thought my response to the question served. When I answer a question here I do attempt to do so in as concrete a manner as possible and with the clearest language I can muster. So ... obliged to all who appreciated my answer.

Well explained

End user of mathematical model is all of us, it goes round. For example AquaCrop Model developed by FAO, it goes to a farm manager, then to farmer, then increased productivity means all of us get food at cheaper prices. Once the model works FAO then improves it and the cycle starts again.