Information Systems 12 E238 TEE Questions 1997

You can BUY the question paper (Information Systems 1997)
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 primary memory in a computer is used to hold both instructions and data. If part of the primary memory is ROM, what could this be used for?

(a) Temporary storage
(b) Level 2 cache
(c) User preferences
(d) Boot program

2. Many current computers and operating systems are referred to as “32 bit”. To what does the number “32” refer?

(a) The number of bits in a word
(b) The number of registers in the CPU
(c) The size of primary memory
(d) The number of bits into which tasks will be broken

3. Which factors govern the rate with which data can be delivered to the CPU through a data bus?

(a) Bus speed and RAM size
(b) Rotational delay and clock speed
(c) Bus speed and bus width
(d) Bus width and seek time

4. What is parallel processing?

(a) The concurrent execution of multiple tasks by a single processor.
(b) The use of multiple processors to simultaneously execute instructions.
(c) Parallel processing is a network of processors that share the same resources.
(d) Parallel processing is the physical arrangement of processors on a computer’s motherboard.

5. A family wished to connect their home computer to the Internet using a standard telephone line. Why does this family need a modem?

(a) Without a modem, the maximum data transfer rate is only 300 bits per second
(b) Modems have encryption algorithms built into their circuits to prevent unauthorised users from reading the transmissions.
(c) A modem is required to translate between the analogue signals transmitted through the standard telephone line and the computer’s digital signals.
(d) A modem performs the necessary translations between the Internet communication protocols and those protocols understood by the home computer.

6. This table compares two types of network cabling. Which entries should be substituted for 1, 2, 3 and 4 to complete this table correctly?

	UTP	Optical fibre
Bandwidth	Small	Large
Security	(1)	(2)
Cost per metre	Small	Large
Cost per Megabyte	Large	Small
Susceptibility to electromagnetic interference	(3)	(4)
Distance between repeaters	100 m	50 km

(a) 1: Secure; 2: Not secure; 3. Susceptible; 4: Not susceptible
(b) 1: Secure; 2: Not secure; 3. Not susceptible; 4: Susceptible
(c) 1: Not secure; 2: Secure; 3. Not susceptible; 4: Susceptible
(d) 1: Not secure; 2: Secure; 3. Susceptible; 4: Not susceptible

7. In the OSI-ISO network model, the data link layer describes

(a) the packaging of data and how error detection and correction are handled.
(b) the data transfer mechanism between network nodes.
(c) how different network nodes can communicate with each other.
(d) the electrical connections required.

8. A software metric is

(a) a measurement of some software characteristic.
(b) the Australian decimal equivalent of an American software measurement.
(c) a methodology for software development.
(d) a programming language.

9. Which of the following best describes the top down systems development technique?

(a) At first, most of the components are implemented as stubs.
(b) Individual components are made first.
(c) Upper management controls the development process.
(d) The system is developed iteratively.

10. Which of the following is not an Information System design tool?

(a) Entity relationship diagram
(b) Data flow diagram
(c) Structure chart (diagram)
(d) Gantt chart

11. Which of the following is not a benefit of distributed information processing systems?

(a) Failure of a hardware component has less impact.
(b) Remote sites are able to operate in their own time zones.
(c) Local access to data improves response time.
(d) Data integrity is improved.

12. In database terminology, what is a relation?

(a) A link between two tables
(b) A table
(c) A foreign key
(d) An index

13. Consider the following statements about relational databases:

You can have relations without relationships.

You can have relationships without relations.

With reference to these statements, select the best of the following alternatives.

(a) Both statements are true.
(b) The first is true but the second is false.
(c) The first is false but the second is true.
(d) Both statements are false.

14. A compiler is

(a) A person with overall responsibility for a project.
(b) A structure to keep track of the contents of a disk.
(c) A hardware device to interface components.
(d) A program to translate one computer language into another.

15. Which of the following is not a characteristic of a typical fourth generation language (4GL)?

(a) Using human orientated terminology.
(b) Supporting nonprocedural programming.
(c) Providing access to machine code.
(d) Speeding the development of applications.

END OF PART A

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PART B Short Answers (25 Marks)

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

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Question 16. (3 marks)

Study the following extract from a newspaper article.
(Note: Not all of the article is reproduced here.)

MILLENNIUM BUG TO BITE COMPANIES HARD
At the end of the sixties a number of computer companies found that their computer programs were failing. On investigation, these companies found that the programmers had recorded the current calendar year as a single character—based on the assumption that the prefix will be “196”. The programs worked well during the sixties, but with the arrival of 1 January 1970, the computer programs reported the current date to be 1 January 1960. Suddenly,	simple arithmetic calculations based upon the current date produced ridiculous results. Of course, this could not happen today, or could it? It is estimated that the “millennium bug” will cost commerce $500 billion to fix. A company has the “millennium bug” if any of its computer programs record the calendar year using only the final two characters. We do not have to wait until 1 January in the year 2000 before witnessing the effects of the bug.	Some credit card companies have cancelled customers’ accounts as the company computer has reported that the credit cards were due to expire in the year 2000 and the program recorded this expiry year as “00”. Later, when checking the validity of credit transactions, those cards were deemed to have passed their use by date. Companies that do not take action to eradicate the millennium bug….

(a) Describe a strategy that you could use to determine if an organisation is likely to be affected by the millennium bug? (6 lines)

(b) What needs to be done to fix the millennium bug? (3 lines)

Question 17. (3 marks)

The classical systems development life cycle may be outlined by the following sequence:

1. Preliminary investigation
2. Analysis
3. Design
4. Implementation
5. Maintenance

(a) How does the preliminary investigation differ from the analysis? (4 lines)

(b) Some information systems professionals (“generalists”) have a broad but possibly shallow knowledge of a wide variety of technologies, whilst others (“specialists”) have a detailed knowledge of a limited area. During which stages of the systems development life cycle would each type of professional be most usefully employed? (2 lines)

Question 18. (2 marks)

When the school canteen needs to order food supplies it creates an order in triplicate using the suppliers’ price list file to determine who the order is to be sent to. One copy of the order is filed and another sent to the Accounts Department in the administrative building.

The following data flow diagram was intended to describe this system, but was poorly constructed. Identify, by writing notes on the diagram, four errors in the data flow diagram.

Question 19. (4 marks)

To what extent would you describe each of the following as an information system.

(a) A television set (working) (6 lines)

(b) An automatic teller machine (6 lines)

Question 20. (3 marks)

In a relational database system:

(a) What is a relationship? (2 lines)

(b) What is a tuple? (2 lines)

(c) What is an attribute? (2 lines)

(d) What is a primary key? (2 lines)

(e) What is a foreign key? (2 lines)

(f) What is an index? (2 lines)

Question 21. (3 marks)

(a) Distinguish between a CPU’s control unit and its arithmetic logic unit. (6 lines)

(b) What are registers? Describe two registers used by a CPU. (4 lines)

Question 22. (1 mark)

What do the abbreviations RISC and CISC represent? (1 line for each abbreviation)

Question 23. (2 marks)

Provide three reasons why most software distributors use CD-ROMs for the physical distribution of software packages. (6 lines)

Question 24. (3 marks)

In attempting to describe the operation of a facsimile machine to a friend, a student described the facsimile machine as a “scanner, modem and printer—all stuck together”. Explain the operation of a facsimile by expanding on this simple description. (10 lines)

Question 25. (1 mark)

How does data terminal equipment differ from data communications equipment? (4 lines)

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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Question 26. (23 marks)

A relational database system has been set up to assist with the management of this year's Tertiary Entrance Examinations (TEE). The following are tables used in this database. Primary keys are underlined.

STUDENT (student-ID, student-name, date-of-birth, school-name, aggregate-score)
SCHOOL (school-name, address, phone, principal)
TEE SUBJECT (subject-ID, subject-name, exam-date)
STUDENT SUBJECT (student-ID, subject-ID, exam-mark, school-mark)

• A student's aggregate-score is derived from the school-mark and exam-mark in all subjects.
  
• Some data is already recorded in the tables and is shown below.
  
• Some records have column values set to 'null'. The 'null' value is not the same as zero or a blank. It means that data is unavailable or unknown. The TEE database does not permit a primary or foreign key to have a value of 'null'. Other fields except for student-name may have a value of 'null'.
  
• Each student enrolled has a student-ID number that is used for all his or her subjects.

TEE SUBJECT
subject-ID	subject-name	exam-date
INFOSYS	Information Systems	12/11/1997
ECON	Economics	15/11/1997
GEOG	Geography	23/11/1997

STUDENT SUBJECT
student-ID	subject-ID	exam-mark	school-mark
1003	GEOG	null	56
1003	ECON	null	78
1452	GEOG	null	80
1452	ECON	null	68

(a) Draw a diagram in the frame provided to represent the database design. Show all tables and their attributes (primary and foreign keys and non-key attributes) and underline the primary keys. Mark the foreign keys with the code 'fk'. (half a page available) (5 marks)

(b) Complete the following grid giving details of the primary and foreign keys in the remaining three database relations (tables). Note that the first row has been completed for you. (3 marks)

(c) This grid shows details about the relationships between the tables. Complete the grid by placing an X in each row. Note that the first row has been completed for you. (1 mark)

(d) Examine the STUDENT table: (3 marks)

(i) On which column (attribute) other than the primary key might you put an index. (1 line)

(ii) Why? (2 lines)

(iii) Why must the aggregate-score column be optional? (that is, why must it allow for a null value to be stored?) (3 lines)

(e) Add the following data to the four tables: (7 marks)

(i) JOHN MURPHY and MARY KANTOR are enrolled in Information Systems. The have school marks of 50 and 52.

(ii) SAMMY LEE, a student at WA HIGH applies to sit for the TEE. His student-ID will be 1699. He was born on 18th December 1979.

(iii) SAMMY LEE is the first student to be enrolled in the new subject "Asian Culture". The exam date has been set for 11th November 1997. His school mark is currently unavailable.

(iv) JANE SMITH is a mature age student (born 14 March 1964) sitting Information Systems this year but she is not enrolled in any school.

NOTE:

• You may not change the structure of the database.
• You may leave null a column where there are missing details only if this is permitted in the TEE database, otherwise invent suitable data.
• You are not required to complete every blank row in the tables.

(f) MARY KANTOR telephones the TEE administration office and wants to know the dates of all her TEE examination. Explain how the database tables would be accessed to get the required information. (12 lines) (4 marks)

Your answer should describe:

• the order in which the tables are accessed
• the key(s) used
• the number of records read at each stage
• the data retrieved

Although the question doesn't suggest it, you could have used a table to put your answers in, or you could write the answer as a series of sentences. The table might have a structure like this.

	Table	Access key	Access key value	No of records retrieved	Attribute retrieved	Attribute value
1
2
3
4
5

Question 27. SuperShopper Supermarket Chain (19 marks)

The SuperShopper supermarket chain operates in the following manner. All produce is supplied from the central depot. Every item sold is labelled with a unique code, which is entered by the checkout operator along with the quantity. A disk file from head office contains a record for every item code giving item description and recommended price. Each supermarket is run by a manager who can choose to charge the recommended price or some other price to suit local conditions. Typically this is used to offer "specials". The computer system therefore keeps a separate file giving special prices for selected items. The manager will maintain this file by adding and deleting items from it. When a customer reaches a checkout, the item code will be checked against the specials file and the price in that file used. In the event that there is no item of that code in the specials file, the price from the head office file will be used. The customer gets a receipt containing the item descriptions, quantity and price.

(a) (12 marks)

Draw a data flow diagram covering the operation of this system. (space of 3/4 page)

(b) (3 marks)

This system works well for pre-packaged items, which are all the chain currently sells. However, the possibility of expanding the range to fresh food is being considered. In particular it is felt that there would be a market for fresh fish. The customers would choose a fish, possibly even catch one from a tank, and take it to the fish counter for scaling. One anticipated difficulty lies in identifying the type of fish, since the staff may not have the required expertise, and prices of different species might vary widely. It is proposed to develop a computer system to identify fish at the checkout, possibly by capturing an image or by some scientific measurement.

For a system of this nature, which development methodology would you use? Give reasons for your answer. (6 lines)

(c) (4 marks)

Until the automatic computer identification system is working adequately, the company is prepared to employ fish experts to identify the fish (visually). It is not possible to have an expert at every supermarket.

Describe the equipment required to enable the experts to identify the fish for the checkout staff. (12 lines)

Question 28. EFTPOS transaction (18 marks)

Study the following Nassi-Schneiderman diagram depicting the operation of an EFTPOS (electronic funds transfer point of sale) transaction. This is a very generalised view of the EFTPOS transaction and does not elaborate on the processes involved.

Swipe card to determine account

Key in withdrawal amount

Key in account type (savings/cheque/credit)

Enter the personal identification number (PIN)

When the account matches the PIN and there are enough funds in the account, transfer the amount to the store’s account

Print out a transaction receipt showing the success (or otherwise) of the transaction

(a) (12 marks)
Using either a Nassi-Schneiderman diagram or pseudocode, reconstruct this algorithm such that it shows:

• only three attempts are allowed for entry of a valid PIN
• if, after three attemps, a valid PIN is not entered, a warning message is displayed upon the operator’s screen.
• the transaction receipt displays either one of the following messages,
  • either i) the text “Transaction Approved” and the amount withdrawn from the account
  • or     ii) the text “Insufficient Funds” when the PIN matches the account but there is not enough money available for the transaction to proceed
  • or    iii) the text “Incorrect PIN” if the PIN is not successfully matched against the account.
    (one page available)

(b) (6 marks)
EFTPOS (electronic funds transfer point of sale) transactions are very much a part of the retail industry. Outline the network security and privacy issues that should be considered when planning for the installation of an EFTPOS system. (one page available)

END OF QUESTIONS