SL 2.6—Modelling process
- Syllabus
- First assessment 2021
- Objective
- —
- Level
- HL
A model is a cycle: translate, test, revise
To model a situation, define variables and units, choose a functional form, estimate parameters, compare predictions with evidence and revise or qualify the model.
The context determines what counts as a reasonable assumption. Keep a train/test or observed/predicted distinction when possible, and inspect whether errors are random or systematic. A model that fits one interval may fail outside it.
A delivery-time model based on distance may work for local routes but overpredict long routes if motorway travel changes the relationship. Refit or split the model rather than hiding the systematic error.
The calculator selecting a curve is not the modelling process. The final claim must include assumptions, units, validation evidence and a domain of use.