chapter 3 (3)

Question 1

isomorphism

Answer 1

is minimally a one to one correspondence between each feature of the model and of the target. As we have seen, models typically arent exactly like the target systems they represent

Question 2

abstraction

Answer 2

omitting or ignoring certain known features of the system

Question 3

Idealization

Answer 3

including features the target system doesnt have

Question 4

abstraction and idealization serve different goals

Answer 4

Modelers often disregard many properties of their targets to focus on a limited set of features deemed important for the purposes at hand.

Like abstractions, idealizations are a way of simplifying the model, enabling scientists to focus on the bare essentials of the phenomenon theyre interested in whithout getting lost on complicated details. but whereas abstraction involves leaving features of the target out of the model idealizations are properties ofthe model that the target doesnt actually hvae.

Question 5

several features are desirable for models to have. include

Answer 5

Accuracy (models relaistically representing its target)

Generality (applying to range of related target systems)

Precision (providing exact information)

tractabiity (ease of use)

Robusteness (stable behavior across different assumptions)

Question 6

Accuraccy

Answer 6

Representing more actual features of a target system tend to be more descriptively accurate or realistic. A model representing all and only the actual components and features of its target, as it actually has them, would be a model that is maximallyaccurate

Question 7

Generality

Answer 7

A model is more general when it applies to a greater number of target systems. Generality is a desirable feature of models insofar as it enables models to be reused in av ariety of circumstances and more signifcantly because general models make it possible for scientists to discern what a variety of phenomena have in common with one another

Question 8

Precision

Answer 8

A model is more precise to the extent that it more finely specifies features of the target.

A climate model that allows scientists to predict how much warmer the global average temperature will be in 30 years within a range of 1+- degrees celcius is more precise than a model that allows them to predice a 5+- degree celcius range of temperature increase in 20 years

Question 9

Tractability

Answer 9

THe ease of developing and using a mondel

this could involve different considerations for example the time it takes to run a model on a computer or whether the equations of a mathematical model have exact solutions

Question 10

Robustness

Answer 10

A more robust model is one that changes less despite variation in its assumptions. Consequently robustness is a measure of insensitivity to the features that differ from the target including the models abstractions and idealizations. normally scientists dont want their models predictions to be sensitive to such features. To be trustworthy the predictions should be based as much as possible on known similarities between the model and target.

Question 11

Trade off

Answer 11

Considering these valuable features of models notice ow and why each is limited. Increasing one feature often comes at the cost of others