Simulation - A Practical Guide to Teaching Computing and ICT in the Secondary School - page 110

Task 6.4

Key terms for Modelling
The passage above by no means includes all the technical terms associated with
the concept of computer Modelling.
Discuss with a colleague additional words you would include in your list, and
identify activities you might ask pupils to engage in, to increase their understanding
of these terms ( see Resources: Theory of Modelling).

CONTROL
A Control system should be regarded as a method of achieving a specified end, or
an event involving direction by a computer. It usually entails:

1 A change in the status of data or a device.

2 The interaction of a set of parts of the system working together.

Control systems in schools, dependant on context and the resources available, can
be virtual and/or modelled. It is essential that you encourage pupils from the very
start to identify the overarching reason(s) for the specified end or event, before they
can make real sense of the role of the parts. Avoid the temptation of concentrating
on the discrete at the expense of understanding the whole. For example, you
could establish with pupils that safety is the main purpose of a Control system for
monitoring the number of people entering and exiting a given space at a concert
or a sporting venue. Having decided what you want to control, specifying how
the parts of the system should behave will follow more readily. This could mean
that you engage in a meaningful discussion about the most important outcome of
the monitoring system: perhaps an alert sent to appropriate personnel warning of
potential overcrowding is triggered once a predetermined total is reached. Hence
it is much easier to establish that parts for counting, comparing totals and issuing
warnings are required, and work out how they interrelate.

Task 6.5

Systems
The systems approach to Control makes it much easier to apply what has been
learnt from the familiar to the new and unfamiliar. How would you help pupils to
recognise the learning they could apply from this approach to other disciplines?

A Control system usually contains:

1 A computer or microprocessor.

2 An interface which converts signals between the sensors and the processor.

3 A control program which manages data from input sensors and sends signals

to output devices or actuators.

Pupils need to understand that signals can commence on a one-way journey
(open loop), or may be redirected and used to provide feedback (closed loop) that