Forum Comments

What's a model?
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Peer Models Network Admin
May 01, 2020
There are lots of types of models! The type that the PMN deals with are scientific models. These models are representations- of a system, or a phenomenon in the world- which scientists build to help think and reason about it, know more about how it works, and solve problems relating to it. There are MANY types of scientific models, but the kind that PMN deals with are computer models. This means scientists use a computer to build the representation, and then use the computer's output to think and reason about different problems. Here's just one example: imagine an emergency room. An ER is a complicated system, with people coming in and out, needing different services, and looking to accomplish many different goals (e.g., keep waiting times down, optimize various health outcomes, and so on). It would be very hard to understand every aspect of an ER by just thinking about it in your head. By building a computer model of an ER, scientists can think about different relevant questions and get better answers to them- like, how many people tend to come to a certain ER on different days, at different times? What services do they tend to need? So how many different specialists should be working at a particular time? And so on. We should point out that to build a model, scientists generally need information (also called data, or evidence) to put in it (this leads to another question about how models are built, which we will leave for another time). Anyway, this is just an example- but it helps show what we mean when we say "a computer model is a representation that scientists use to think through problems". If you have further questions, let us know!
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Are all models accessible to the public?
In Forum
Peer Models Network Admin
May 01, 2020
Yes, all models on the PMN are accessible to everyone.
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Why do you collect public feedback on models? Shouldn't model evaluation be left to experts?
In Forum
Peer Models Network Admin
May 01, 2020
Good question! First off, modelling is definitely something that requires considerable expertise- often, it takes several people with different types of expertise to build one model. And it is widely agreed that it's beneficial to have models evaluated by other experts outside the modelling team (this is the principle behind the scientific peer review process). However, modelling doesn't occur in a vacuum: the process requires making a number of social value judgments, decisions that can't be made just using scientific evidence and logic alone. For example, the decision about what potential treatments or policies to examine in a model is a value judgment. In addition, models generally must leave out some amount of information, and this is a judgment call. To make it, modellers need to decide what is most important to know and what sorts of losses of information are tolerable. Furthermore, there are many judgments in modelling that have to do with how much certainty we need before incorporating a particular piece of evidence into a model, or before making a conclusion about something. These are just some examples of value judgments in modelling (if you want to more detailed information, please check out Dr. Harvard's recent publication: https://www.sciencedirect.com/science/article/pii/S0277953620301945?via%3Dihub But the take-home message is that, although modelling does require a good deal of scientific expertise, not every decision that is involved in the process is a strictly scientific decision. On the contrary, many modelling decisions draw on social and ethical values around what is most important to know, what are acceptable and worthwhile treatments and policies to explore, and what sorts of errors are essential to avoid. For all of these reasons, we think it is good to start building ways for members of the public to give input to modellers, including patients who are affected by a health condition being modelled, or anyone affected by a public health policy. In addition that, we think there is potential benefit to building ways for experts from different disciplines to talk and collaborate on new approaches to modelling, rather than experts speaking only to people in their own discipline. All of that said, we would still emphasize the importance of the sort of model evaluation that is carried out by experts within specific fields, wherein significant expertise is built up over time
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Peer Models Network Admin
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