 We already know the saying “Garbage in = Garbage out”  We know that bad data entering a system can have strange results on the data leaving the system after it is processed…  We need to make sure data is accurate so that useful information can be produced.  We also need to make sure that information is passed on within a given period of time to ensure it remains useful.

 Air traffic controllers need to know where all planes are at all times.  In order for them to put their planes into a formation around the airport they need to have real time information.  If they receive information about the position of a plane with a delay time of 30 seconds they may instruct a pilot to fly into a location they believe is available…but it isn’t…that would be bad.

 Explain why it would be important for a student to receive his grades on time and not a week later.  Explain why it is important that a take away Chinese restaurant needs to ensure that a placed order is correct.

 We have already covered accuracy of information back in AS…  We can use validation and verification checks to ensure data is accurate.

 These ensure data meets certain criteria.  For example: › Range checks ensure values are entered within a certain range. › Input masks ensure we enter data in the correct format. › Type checks ensure we enter the correct data types.  For more examples, look at the presentation called validation and verification.

 These ensure we have entered what we meant to enter.  For example, a double entry check will ask us to type in something twice…  This makes sure we have typed it in correctly and as we expected.  When you are asked to change your password you are often asked to perform a double entry verification check.

 Real time systems require that we process and output a response within 4 seconds.  An online booking system needs to update ticket sales in real time to avoid double booking.  Air traffic controllers need real time systems in place to ensure accuracy.

 Some organisations do not require real time systems…but they still need to pass on information to other people swiftly.  Rules have to be in place to ensure information is passed on quickly.  In the Chinese restaurant, the telephone operator must pass on the order to the chefs before they take another call. › This will ensure orders to not back up and means customers will get their orders quickly.

 Describe one consequence of share prices being inaccurate on trading days.  A person uses an ATM and checks their balance. They are surprised to find more money than they expected…especially considering they spent a lot of money the previous day. They take out more money but then later find out that they have gone over drawn. Why might this be?  Identify three methods to ensure data is transferred accurately and speedily.