1 Representations of the actual system
2 Smaller versions of the real system
3 Simpler versions of the actual system
1 Three Dimensional Structures
2 Sketches
3 Computer simulations
4 Diagrams
5 Math formulas
1 A car
2 building
3 A person
4 The solar system
5 The actual system
6 The object under study
1 A toy car
2 Sketch of building we are going to build
3 A diagram of a person
4 A computer simulation of the solar system
5 A Three Dimensional mini rocket
6 A diagram of a bacteria
1 Help us to identify the parts of a system
2 Determine how the system works
3 Make predictions about the system
4 Help diagnose problems in the system
