contains scenario 2 from a 2010 question paper for information systems may/june

1. May/June 2010 (31)Scenario 2 Blake Walsh

2. Scenario The Niagara Drug Company is a large pharmaceutical company which develops, manufactures and markets new drugs. They are developing an expert system to help chemists in their research. Once a new drug is developed, the company needs to market it. They have a market research team who use primary research techniques. The company’s many processes are monitored and controlled by microprocessors.

3. Question 4 (a) They are developing an expert system to help chemists in their research. Once a new drug is developed, the company needs to market it. They have a market research team who use primary research techniques. Describe how the knowledge base of the expert system could be set up. [2]

4. Answer Any two points covering either design or installation from: - knowledge engineer collects information from experts and from other systems (needs at least two sources) - a reference to data mining - a knowledge base is designed - implement forward chaining in system - a rules base is designed to be used by the inference engine

5. Answer - develop a suitable user interface with validation rules - design the questions for a user - create an explanation system for output - system would be checked using data with known outcomes - production of user manuals/training of staff in E/S use - a test plan designed with known answers from experts - an implementation plan set up

6. Question 4 (b) They are developing an expert system to help chemists in their research. Once a new drug is developed, the company needs to market it. They have a market research team who use primary research techniques. Explain how the knowledge base of the expert system will be edited. [3]

7. Answer Any three from: - using built in text editor of the system - system adds new facts automatically to database - from company server - remote access to knowledge base and amended - by research staff - using text editor directly on knowledge base

8. Comments This question is leads on from IGCSE ICT and candidates really should be familiar with the concept of setting up a knowledge based expert system. They were required to provide more specific answers than at IGCSE and many failed. It was good to see some candidates reaching an A2 standard. (a) Design and installation only to earn marks (b) Very few answers showed understanding of the need for an editor to update a knowledge base.

9. Question 5 They have a market research team who use primary research techniques. Describe the primary market research techniques that would be used. [5]

10. Answer Any five points from: 1 mark for identifying method, 1 for expansion - CAPI (computer assisted personal interviewing) - sit in front of computer and answer on screen questions - interviewer asks questions prompted by computer - CATI (computer assisted telephone interviewing) - basically call centres used in this technique - computer dials phone numbers of target audience and then interview takes place using script

11. Answer - CAWI (computer aided web interviewing) - database of people willing to take part in research - customer logs on to web site and answers questions - use pop ups/adverts on selected web sites - Use of person-person interviews and techniques

12. Comments This proved a popular question and many Centres had taught these terms and their candidates scored well.

13. Question 6 The diagram below shows one of Niagara Drug’s chemical processes. This process is dependent on pH and temperature. Sensors are used to relay back information. Describe how the sensors and microprocessor are used to control the conditions in the chemical process. [5]

14. Answer Any five points from: - pH sensor and/or temperature sensor send signal to microprocessor - signal converted to digital by ADC if signal is analogue - microprocessor compares input values … …against previously stored range - if pH too low, sends signal to actuator to open valve and add acid - if ph in range then do nothing/signal sent to close valve - if temperature too low, sends signal to actuator to turn on heater

15. Answer - system continually monitors pH and temperature - if temperature is in correct range then do nothing/signal sent to actuator to turn heater off - microprocessor sends signals to control room displays to allow operators to monitor conditions - microprocessor can send signals to warn operators of malfunction - sensors also on heater and acid feed … - …to warn of (local) malfunction e.g. out of acid/heater not working

16. Comments Candidates should be used to control questions from IGCSE ICT. It was worrying how few candidates understood the concept of an acceptable range rather than a specific reference value. The use of ADC was good but few understood the use of actuators. Centres need to ensure that the candidates understand that a sensor does not decide what to do it, simply inputs data into a microprocessor via an ADC.