Modelling ICT - Q & A

1. Identify three characteristics of modelling software. 

The ability to change variables within the software; asking what-if questions to see what the result of changing variables might be; formulas and functions to carry out the mathematical calculations that form the basis of the model; automatic recalculation of formulas and functions; rules that define how the model behaves; layers of abstraction so that different parts of the model can be viewed and analysed separately.

2. Describe, using examples, how a spreadsheet could be used to model the costs or savings to an organisation of moving premises.

Variables can be used to change the rental costs; formulas and functions can be used to calculate the total cost of each of the premises; graphs can be used to show the distances from important locations for each of the premises; goal-seek can be used to find out what the rental cost would need to be to match the current costs; conditional formatting could be used to show the cheapest and most expensive options. 

3. Describe two advantages of using a simulator for pilot training. 

Fuel costs can be saved by not having to fly real aircraft; wear and tear of aircraft does not take place during training, which saves on maintenance costs; instructors do not need to be present for all training sessions; unforeseen or dangerous circumstances can be invoked to test the pilot’s reaction without experiencing the real danger. 

4. Describe one disadvantage of using a simulator for learning to drive

 The learner driver does not get to experience the real reaction of a car; the simulator is only as good as the model it is based upon, meaning that the simulator will not react exactly the same as a car would.

Exam-style questions

1 Q: The spreadsheet model is going to be used to calculate the costs of using each car. a Explain three advantages of using a spreadsheet to model the costs of using each car. [3] b Explain one disadvantage of using a spreadsheet to model the costs of using each car. [1] [Total 4]

The driving school is considering purchasing a simulator to help students to learn to drive.

1 a  Any three of the following [3]: 

 • Variables can be used to change the distances travelled [1]. • What-if questions can be asked such as ‘what will be the cost if the car travels 300 miles?’ [1].

* Formulas and functions can be used to calculate the total cost [1]. • Graphs and charts can be used to compare the costs of each car [1]. • Formulas and functions will automatically recalculate so results can be seen instantly [1]. • Conditional formatting can be used to show cars that cost a specific amount [1]. • Goal-seek can be used to find out the optimum speed to travel at [1]. 

 b Any one of the following [1]: 

 • The model will only be as good as the rules [1]. • The speed the car is travelling at will need to be taken into account [1]. • Unforeseen circumstances such as traffic jams will affect the costs [1].

2. a Explain why a simulator would be used for this purpose. [4] b Explain the disadvantages of using a simulator for this purpose. [4]

2 a Any four of the following [4]: Review Copy - Cambridge University Press - Review Copy Dangers such as hazards, other cars, pedestrians, etc. can be avoided [1] because the simulator can model these instead of using the real road [1]. Learners do not always need to have an instructor present [1] because the simulator does not pose any danger [1]. Learners can experience circumstances they may not normally encounter [1] such as a child running into the road [1] because these can be modelled [1]. The learner can practice complex manoeuvers without holding up other road users [1] because the simulator can model the presence of other traffic [1].

b.  Any two of the following (2 marks for each point) [4]: Review Copy - Cambridge University Press - Review Copy • There are too many variables to be modelled [1] and so the simulator won’t always match a real car [1].

There is no consequence for making a mistake in a simulator [1], which may lead to drivers becoming over confident when using a real car and making mistakes which cause damage or an injury [1]. • Not all driving situations can be replicated [1], meaning that the simulator won’t give a full experience of driving a car [1].

Simulators can cause nausea [1] that wouldn’t happen in a real car [1]. • The driving school would need to invest in the purchase [1], which could be extremely expensive for a small school [1].

3. Evaluate the use of simulators for nuclear science research.

Any four from the following (2 marks for each) [8]: 

 • Nuclear science is very dangerous so experimenting with simulations is much safer. • Variables such as coolant temperature can be changed to see the effect on nuclear reactions. • What-if questions can be asked to see what the effect of changes to variables would be. • Goal-seek could be used to see what variables need to change to achieve a desired reaction. • The simulation could be sped up rather than waiting several days or years to see a real world outcome

* Nuclear simulations require a lot of computing power due to the large number of reactions taking place. • Not all possible inputs can be simulated meaning the results of the simulation would not reflect exactly what might happen in the real world.