Information Systems 12 E238 1999 TEE Questions

You can BUY the question paper (Information Systems 1999)
from the Curriculum Council of Western Australia
for $3.30 (price in September 2004).

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PART A Multiple Choice Items (15 marks)

Attempt all questions in this part. Each question is worth 1 mark. Each question has only one correct response. For each question select the response that is correct. Signify your answer by circling the label (a, b, c or d) of the correct response. If you change your answer, completely erase your original answer. Questions where two or more responses are selected will score no marks.

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1. The term 32x CD-ROM refers to the CD-ROM’s:

(a) Speed of rotation.
(b) Total data capacity.
(c) Degree of oversampling by the laser.
(d) Compression algorithm used.

2. The term RISC stands for:

(a) Required integrated system compliance.
(b) Reduced instruction set computer.
(c) Real-time internal system clock.
(d) Read instruction set cache.

3. Two computer users attempt to exchange data by swapping floppy discs. It turns out that neither can read the other’s disc, although they have the same operating system and can each read their own discs. From this we can conclude that the most likely cause is:

(a) The discs are faulty.
(b) The users are not inserting the discs correctly.
(c) One or both disc drives are out of alignment.
(d) The computers are incompatible.

4. A scanner is available in two models: SCSI or parallel. To what do these models refer?

(a) Their method of connection to the computer.
(b) Their loading mechanism.
(c) The resolution of the resulting images.
(d) The kind of image file produced.

5. A modem is designated by the term 56K. To what does the number 56 refer?

(a) Speed at which the modem can transfer data.
(b) Number of K type pins on the connecting cable.
(c) Maximum amount of data buffered by the modem.
(d) The digital standard supported by the modem.

6. Which of the following statements about the microwave communications medium is incorrect?

(a) Microwave signals form the basis of all local area networks.
(b) Microwave transmissions are economical due to the low cost per bit.
(c) Microwave repeaters must be placed in line of sight.
(d) Microwaves have a large bandwidth—typically between 1 and 30 GHz.

7. Which of the following incorrectly describes the relationship between information systems and management information systems (MIS)?

(a) A MIS is a system for managing an information system.
(b) An information system is a way of implementing a MIS.
(c) An information system may include a MIS as a component.
(d) A MIS provides information of a more strategic nature than does an information system.

8. If you were developing an accounting system bottom up, the very first thing you might code would be:

(a) The system menu.
(b) A routine to calculate compound interest.
(c) The last item to be included in the system menu.
(d) A report for the auditors.

9. Complete the following. Logical data flow diagrams are used to:

(a) Design communications networks.
(b) Outline computer algorithms.
(c) Document the information passed between parts of a system.
(d) Schedule project management tasks.

10. Which of the following statements about distributed information systems is always true?

(a) A distributed information system uses a relational database.
(b) A distributed information system uses modems.
(c) A distributed information system has more than one CPU.
(d) A distributed information system uses computers from more than one manufacturer.

11. Which of the following is included in data flow diagrams?

(a) File structures.
(b) Data structures.
(c) Process controls.
(d) Data stores.

12. The major reason relational databases are made up of normalised tables is to:

(a) Reduce the memory required.
(b) Decrease the response time.
(c) Reduce the storage of redundant data.
(d) Decrease the number of tables required.

13. Which statement is correct? Relations in Third Normal Form must have:

(a) All non-key attributes dependent only on the key.
(b) A key consisting of more than one attribute.
(c) A key consisting of just one attribute.
(d) No attributes which are not part of the key.

14. Which of the following statements is true?

(a) All Third Generation Languages were created before 1990.
(b) Third Generation Languages ensure structured programming.
(c) All Third Generation Languages were designed for Internet Programming.
(d) When using a Third Generation Language, the user writes procedural code.

15. You are writing an application where you need to explicitly manipulate the machine registers. Which of the following types of computer language would be suitable?

(a) Third generation language.
(b) Fourth generation language.
(c) Assembler/machine code.
(d) Data manipulation language.

END OF PART A

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PART B Short Answers (25 Marks)

Answer all questions. Write your response in the spaces provided in this Question/Answer Booklet.

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16. (a) What is encryption? (2 lines) (1 mark)

(b) What is decryption? (2 lines) (1 mark)

17. In terms of data communications, what is one difference between a bridge and a router? (3 lines) (2 marks)

18. In this “information age” a number of social commentators have suggested that we are “too dependent” upon computer technology. Describe two examples of technological dependence that support the commentators’ suggestion. (6 lines) (2 marks)

19. A project has been estimated to take 10,000 hours of work. Assuming that a person will work for 2,000 hours in a year, this would imply that the project would take about 5 years if staffed by one person. Alternatively, one might employ 20,000 people to complete the project in 30 minutes. If the project were an information systems development project, neither of these approaches would be reasonable. Explain why, giving two reasons in each case. (8 lines) (2 marks)

20. One of the phases of the life cycle approach to information systems development is to gather the user requirements. Typically this is done by user interviews and culminates in the “requirements specification” document. How are the requirements determined using the prototyping approach? (4 lines) (2 marks)

21. Software maintenance of computer systems frequently costs more than the original development did. There are three classes of software maintenance. Describe two of them. (6 lines) (2 marks)

22. Many people think that computer systems and information systems are the same thing.

(a) Give one example of a computer based system that is not an information system. (2 lines) (1 mark)

(b) Give one example of an information system that is not computer based. (2 lines) (1 mark)

23. List two reasons why computerised information systems usually store their data on disc, rather than in RAM. (4 lines) (2 marks)

24. What is the difference between analysis and design? (4 lines) (2 marks)

25. “A student can belong to many sports clubs. A sports club has many student members.”

An entity-relationship model of this situation consists of two entities Student and Sports Club with a many to many relationship between them. However, most relational database systems do not directly support “many to many” relationships, but do support “one to many” relationships. Explain, using a diagram or otherwise, how you would change the model to use the commonly supported “one to many” relationship. (0.25 page) (2 marks)

26. Study the following Nassi-Shneiderman diagram. (3 marks)

(a) How many times will the While loop be executed? (0.5 line)

(b) What will be the value in X and Y after the last execution of the loop? (0.5 line)

27. Languages may be either interpreted or compiled. Give one advantage of each approach. (4 lines) (2 marks)

END OF PART B

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PART C Extended Answers (60 marks)

There are four questions in Part C. Answer all of them. Write your answers in this Question/Answer Booklet using the spaces indicated. Label your answers clearly.

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28. CC Design Studio (15 marks)

Lee works as a graphic designer at the CC Design Studio. Lee uses a computer for all the studio’s graphics and makes extensive use of the Internet for communication with the studio’s clients. At present, Lee is working on a suite of graphics for use on a Government web-site. If the Government department likes Lee’s work, the CC Design Studio will win a lucrative contract.

(a) To access the Internet, Lee’s computer has a static IP address and uses TCP/IP as well as HTML.

Explain the roles of IP addresses, TCP/IP and HTML that enables Lee to use the Internet’s World Wide Web. (18 lines) (6 marks)

(b) The newly created designs are responsible for the competitive advantage of CC Design Studio. Mindful of this, the directors have identified 3 major threats to this property:

• Computer viruses

• Hardware failure

• Unauthorised access by competitors

For each of these perceived threats:

(i) Explain how problems could arise (7 lines) (3 marks)

(ii) Indicate what CC Design could do to minimise the chances of these problems occurring. (7 lines) (3 marks)

(iii) In the event that these problems occur, indicate what CC Design could do to reduce their effects. (7 lines) (3 marks)

29. Ettamongah Amateur Dramatic Society (12 marks)

The Ettamongah Amateur Dramatic Society has its own small playhouse theatre. The theatre consists of 26 rows (A-Z) of numbered seats. Due to a generous government grant, the Dramatic Society is able to produce plays for the local community citizens at no charge. However, the Dramatic Society insists upon the citizens reserving their seats for each performance. This reservation activity is conducted by the box office.

When a new play is scheduled, the Dramatic Society provides to the box office seating plans for each performance, which indicate the seats available for the community.

To reserve seats, the citizen goes to the Dramatic Society’s theatre box office and requests from the box office manager a number of seats for a particular performance. The box office manager consults the seating plan for that performance and offers the citizen a number of options. When the citizen selects a seating option, the box office manager updates the seating plan by crossing off the seats taken. The manager then produces tickets for the citizen that details their reserved seats for the relevant performance.

Occasionally, the Dramatic Society will require a report from the box office manager that gives details of the seats reserved for particular performances.

Construct a logical data flow diagram (LDFD) describing the operations of the box office. (1.5 pages) (12 marks)

30. Jigsaw Library (18 marks)

Mrs Stephenson is retired now and spends her time running a jigsaw library for people in her suburb. She requires a database to run on her laptop computer to keep track of her jigsaw library. Your task is to design this database.

She has over 500 jigsaws in stock. She allocates each one a unique jigsaw ID. She keeps details of the number of pieces in a puzzle, its date of addition to her collection, donor name if not purchased, purchase price if purchased, the title of the picture, and the manufacturer’s name. She categorises the condition of each jigsaw as “Good”, “Satisfactory”, “Poor” (1 or 2 pieces missing) or “Unusable”.

Mrs Stephenson lends jigsaws at no charge to her borrowers who are mainly relatives and friends. She allows the borrowers to keep a puzzle for a time they specify up to a maximum of two months. She keeps details of the borrowers’ names and addresses and contact phone numbers. She also records details of each jigsaw borrowed, including the jigsawID, borrower, date borrowed and the date due to be returned. You may assume that each borrower’s name is unique.

When a borrower returns a jigsaw, Mrs Stephenson records the date returned. If the borrower has attempted to complete the puzzle, she asks them what the puzzle’s current conditon is. If this conflicts with the condition she has previously recorded, she changes the condition in her records.

Mrs Stephenson has a problem. Sometimes the borrowed jigsaw, categorised as “Good” or “Satisfactory”, is found to have some pieces missing. The borrower returns the puzzle and complains to Mrs Stephenson who would now like to be able to track the previous borrowers of the puzzle.

Mrs Stephenson would also like to be able to produce a list of all borrowers with overdue loans, their phone numbers, the jigsaw borrowed and the date it was due to be returned.

(a) Produce an Entity Relationship (E-R) diagram modelling a physical design for a relational database to satisfy Mrs Stephenson’s requirements outlined above. On your diagram:

(i) Name all entities, attributes and relationships.
(ii) Identify Primary Keys by underlining them (e.g. PersonID).
(iii) Identify Foreign Keys linking with other tables with the characters -FK after the attribute name (e.g. department-FK).
(iv) Identify any attributes that have null values permitted by including -NP after their name (e.g. Spouse-NP).
(v) Identify any attributes that have values restricted to a set of just a few possible values by including -R after their name (e.g. Month-R).
(vi) Combinations of primary keys, foreign keys, allowed nulls and restricted values may be valid (e.g. SportsClub-FK-R-NP). (0.75 page) (13 marks)

(b) Should Mrs Stephenson delete the record of a jigsaw’s loan after it has been returned? Explain why or why not. (4 lines) (2 marks)

(c) Explain exactly how you would use the database to query the name and telephone number of a borrower with an overdue loan for jigsawID = 98 which was due back yesterday and still has not been returned. (6 lines) (3 marks)

31. Date Conversion (15 marks)

A particular computer system represents dates by year, month and day in the following numerical format: YYMMDD. For example:

The Date	is stored as the integer
8th of December 1997	971208
13th of April 1999	990413
April 25, 2014	140425

(a) Explain, using at least two examples, how this method for storing dates can lead to problems. (4 lines) (2 marks)

A better method for recording dates would be YYYYMMDD. Using this method, the 8th of December 1997 would be recorded as 19971208.

To convert the older YYMMDD format to the YYYYMMDD format, the following algorithm is planned.

If date > 500000

then date <—— 19000000 + date

else date <—— 20000000 + date

(b) Using this algorithm, complete the following table. (Note that some of the table has been completed for you. The last “Correct?” column is provided for you to check the accuracy of each conversion.) (3 marks)

Actual date	YYMMDD format	YYYYMMDD format	Correct?
7 March 1933
25 December 1959	591225
30 November 1997	971130	19971130	Yes
26 January 1990	900126
29 February 2000
1 April 2051

(c) This simple algorithm will correctly convert dates for some years only. What is the range of years that produces a valid conversion from the YYMMDD to the YYYYMMDD format? (1 line) (2 marks)

(d) As part of the conversion process, it is decided to check dates for validity since the representation would allow impossible dates to be stored (e.g. 19977766). Part of this process will be to check that the number of days specified is possible for the given month.

The array DaysInMonth has been set up for you with the number of days in each month:

Index	1	2	3	4	5	6	7	8	9	10	11	12
Value	31	28	31	30	31	30	31	31	30	31	30	31

Using pseudocode, provide an algorithm that will receive a year, month and day (each provided as an integer greater than zero) and display a suitable warning message if the day is invalid for the given month. IGNORE LEAP YEARS in this calculation. (6 lines) (2 marks)

(e) To incorporate leap years into this calculation, one approach would be to provide a separate module to identify leap years. Using a diagram or otherwise, show what data would have to be passed into such a module and what would be passed back. DO NOT ATTEMPT to code the module itself. (0.25 page) (2 marks)

(f) Now indicate how you would change your answer to part (d) to use the module you specified in part (e). (5 lines) (4 marks)