Information Systems 12 E238 TEE 1998 Questions

You can BUY the question paper (Information Systems 1998)
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 following tools are used in the IT industry:

Gantt Chart

PERT diagram

critical path analysis

Microsoft Project

Which of the following people would use one or more of these tools for the task stated?

(a) A programmer to define the terms and objects used in a suite of programs.
(b) An analyst to determine if a system is “open” or “closed”.
(c) The project team leader to schedule the development of a new system.
(d) A database designer when normalising data.

2. Part of a Management Information System (MIS) developed for a manufacturing company provides an enquiry screen to display sales volumes over the previous 8 quarters. It does this by extracting individual order details from the company database, then displaying the total quarterly orders in a bar chart.

Which of the following sentences best describes what is happening here?

(a) Data is being converted into information.
(b) Information is being converted into data
(c) This illustrates a “bottom up” design.
(d) This illustrates a “top down” design.

3. Which of the following statements is always true about an open information system?

(a) An open information system is built as a series of objects which open when they receive a message from another object.
(b) An open information system has boundaries allowing the flow of data into and out of the system.
(c) An open information system has nothing hidden inside it.
(d) An open information system has no access security implemented.

4. Which of the following is a small, high speed storage device?

(a) Control unit.
(b) Arithmetic Logic Unit (ALU).
(c) Central processing unit (cpu).
(d) Register.

5. A common practice uses 8 bits to encode a single character. You have an application where this is insufficient and are considering using a 9-bit code. How many characters will this now allow you to represent?

(a) One more character.
(b) Half as many characters.
(c) Twice as many characters.
(d) Nine more characters.

6. A conventional computer will execute instructions one after the other. In most cases, once one instruction has been executed the computer will execute the instruction at the next physical address in memory. Which of the following events will NOT affect this flow?

(a) Calling a module.
(b) An interrupt.
(c) Multiplying a number by zero.
(d) Returning from a module.

7. A computer on the market is described as 260 MHz. To what does the number “260” refer?

(a) The clock speed.
(b) The amount of memory.
(c) The maximum number of tasks that can be executed simultaneously.
(d) The frequency characteristics of the sound card.

8. In the computer store you see a box with the words “6.4 GB” on the outside. Which of the following is most likely to be in this box?

(a) A high resolution scanner,
(b) A hard disk drive.
(c) A laser printer.
(d) A very fast processor.

9. In the ISO-OSI network model, which layer is responsible for the access, transfer and management of files?

(a) The link layer.
(b) The presentation layer.
(c) The application layer.
(d) The session layer.

10. The digital networks standard X.25 defines:

(a) a maximum CD-ROM rotation speed.
(b) error detection and correction techniques.
(c) a method of contention within local area networks.
(d) packet switching protocols used on public data networks.

11. Which statement about database models is correct?

(a) Links between tables in relational databases are held by data values in keys (namely, foreign key and primary key values).
(b) Hierarchical databases store data in sets (and run on mainframe computers).
(c) Network databases make use of inexpensive personal computers linked to the Internet.
(d) In a flat file database, the DBMS manages the links between tables.

12. Which statement about a relation in second normal form (2NF) is correct?

(a) The relation has a primary key that may contain a null value.
(b) The relation contains repeating groups.
(c) All attributes that are not part of the key depend on all attributes in the key.
(d) The relation has no unique key. (There is no non-key attribute that depends on another non-key attribute.)

13. Which statement about a data dictionary is correct?

(a) A data dictionary holds definitions of data, that is, data about data.
(b) A data dictionary holds common data that will be shared between computer systems.
(c) The online version of the Australian Macquarie Dictionary is an example of a data dictionary.
(d) A data dictionary allows computer systems to translate code from one programming language to another.

14. Code in a module may be given access to data either by way of global variables or by passing parameters. Which of the following is NOT an advantage of using parameters?

(a) Modules may be developed independently.
(b) The code executes faster.
(c) The code is easier to maintain.
(d) Modules may be put into a library and reused.

15. Which of the following is comparisons between Fourth Generation Languages (4GLs) and traditional Third Generation Languages (3GLs) is correct?

(a) 3GLs allow faster development of applications than 4GLs.
(b) 4GLs use more computer resources than 3GLs.
(c) 3GLs are easier to use once the programmer has mastered the basics, than 4GLs.
(d) 4GL projects need more programmers than 3GL projects.

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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16. How does an information system differ from a communication system? (3 lines) [2 marks]

17. In a distributed database application, you may choose to duplicate data at more than one location. Give one advantage and one disadvantage of doing this. (4 lines) [2 marks]

18. List four methods a systems analyst might use to gather data about an existing information system. (4 lines) [2 marks]

19. List the steps of the traditional systems development life-cycle. (7 lines) [3 marks]

20. Research shows that over the lifetime of most applications the cost of maintenance greatly exceeds that of development. It is suggested that if programs could be developed without any errors, the cost of maintenance would be zero. Give one reason why this statement is false. (2 lines) [1 mark]

21. What do the acronyms RAM and CD-ROM represent? (2 lines) [2 marks]

22. Why does the efficiency of a computer system improve with the implementation of any of the various types of cache? (4 lines) [2 marks]

23. When a program reads a record from a file stored on a disk, sometimes this results in an immediate access to the disk. On other occasions, however, there may be no apparent disk activity. Explain why this is so. (3 lines) [1 mark]

24. With reference to electronic communication, what is “noise”? (2 lines) [1 mark]

25. Name two error detection techniques used in data communications. (2 lines) [1 mark]

26. Over the past decade there has been a gradual acceptance of international standards for data communication.

(a) Provide one reason why such standards are necessary. (2 lines) [1 mark]

(b) Name one data communications standard. (1 line) [1 mark]

27. The use of passwords is a common security measure on computer systems. This effectively limits access, but it is important that passwords are not discovered by anyone else. List three measures to reduce the chance of this happening. (5 lines) [2 marks]

28. Ultimately, all programs are executed as machine code, Usually, however, they are written in some other language and then translated into machine code for execution. Give two reasons why programs are not written directly in machine code. (3 lines) [1 mark]

29. Predict the output of a program written to implement the following Nassi-Shneidermann diagram. (4 lines) [3 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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Question 30 [20 marks]

Honest John's Bargain Emporium sells a variety of goods very cheaply. To save costs, they use a manual procedure for handling credit card purchases.

The customer first presents the goods and card to the clerk.

The sales clerk checks the card against a list of stolen cards. The police maintain this list. If the card is on the list, the card number, date and time are passed to the police. If the card is not on the “stolen” list, the sales clerk uses the credit card to imprint a credit slip which is then updated with the date and the total price of the purchase.

The credit slip is then passed to the customer who signs the slip and hands it back to the clerk. The clerk checks the customer's signature against that on the back of the card and if satisfied, records the details of the purchase into the sales register and hands over the purchased goods with a copy of the credit slip to the customer. The original signed credit card slip is placed beneath the cash and cheques in the cash register drawer. At the end of each day, all the credit slips are collected, collated and delivered to the Bargain Emporium's creditcompany.

If the clerk is not satisfied that the signatures match, the customer is notified that the purchase is refused and the credit card will be handed over for investigation. The credit card and the credit slip are forwarded to the Police.

(a) The following symbols are used in data flow diagrams. Name each symbol. (4 lines) [2 marks]

circle

square

arrow

open ended rectangle

(b) The analyst first produces the following data flow diagram:

Give four reasons why this diagram is wrong. (4 lines) [2 marks]

(c) An improved top level data flow diagram is shown below:

You are to produce a data flow diagram for the next level of decomposition for the process “handle credit card transaction”. The data flow diagram has been partially finished. Complete the diagram. [10 marks]

(d) Honest John decided that his Bargain Emporium would benefit from being “computerised”. Consequently, he contracted a systems analyst who advised Honest John that the new system would be developed using the prototyping approach.

(i) Describe the prototyping method of systems development. (9 lines) [4 marks]

(ii) State two advantages and two disadvantages of using the prototyping approach rather than the life cycle approach. (7 lines) [2 marks]

Question 31 [7 marks]

(a) A particular World Wide Web (WWW) search engine has the following advanced search features:

abc AND xyz	…returns documents which contain the character strings "abc" and "xyz" in the same paragraph.
abc OR xyz	…returns the documents which contain either character strings "abc" or "xyz" or both in the same paragraph.
"abc xyz pqr"	Use of the quotation marks returns documents which contain the exact phrase "abc xyz pqr".
abc CLOSE(10) xyz	…returns documents which contain the character strings "abc" and "xyz" in the same paragraph as long as the strings are close by. In this example, within 10 words.
abc AND (xyz OR pqr)	Use of the parentheses allows for the logical grouping of commands. In this case the documents would either contain the character strings "abc" and "xyz", or the strings "abc" and "pqr".
abc NOT xyz	…returns documents that contain the character string "abc" but do not contain the string "xyz".
Note: All the search engine command words (AND, OR, CLOSE and NOT) must be entered in uppercase. Apart from the command words, the search engine is not case sensitive.

What search strings would you enter to retrieve documents available on the WWW, which target the following topics? Your search string should minimise the likelihood of the search engine retrieving documents unrelated to the specified topic.

(i) A dessert recipe that includes watermelon, rock melon and ice-cream. (Note: Another name for rock melon is cantaloupe, and ice-cream is sometimes spelt ice cream or icecream.) (2 lines available) [1 mark]

(ii) Information about Gary Larson the cartoonist renowned for drawing The Far Side - a cartoon strip syndicated in newspapers around the world. (2 lines available) [1 mark]

(iii) Information about other men named Gary Larson who are not cartoonists. (2 lines available) [1 mark]

(b) The following all play an important role in allowing someone to access the World Wide Web from their home computer.

• Browser
• URL
• IP address
• DNS (Domain Name Server)
• ISP (Internet Service Provider)
• TCP/IP
• Modem
• PSTN

  Describe the role of each in enabling a student to retrieve information stored on a WWW server in Oxford, England, from her home computer in Western Australia. (16 lines available) [4 marks]

Question 32 [19 marks]

THE WESTERN DOG ASSOCIATION

General
The Western Dog Association is a fictitious non-profit association looking after the interests of pedigree dogs in Western Australia. The Western Dog Association is concerned only with the interests of pedigree dogs. Western Dog Association is affiliated with the National Dog Association (NDA). Membership of the NDA automatically results in membership of the relevant State body, in this case the Western Dog Association. Up to now, owners of mixed breeds have not been accepted as members. The Western Dog Association has an office in Perth, which requires a relational database to keep track of the people and dogs they deal with. All processing of subscriptions and registration of pedigrees are handled solely by the National Dog Association (NDA) from their head office in Melbourne.

Dogs
A pedigree dog is a dog that is registered with the NDA, having satisfied their strict criteria for registration as pedigreed. All pedigree dogs belong to a Breed (e.g. Dalmatian, German Shepherd, Maltese Terrier, et cetera). Dogs have a pedigree name that may be different from the name by which their owner usually call them (e.g. his owner calls the Dalmatian ‘Count Roger of Dalkinghurst’: ‘Spot’).

Licensed dog breeders hold a kennel licence. A holder of a kennel licence breeds only pedigree dogs. No dog can be considered as pedigreed if it was not bred by someone holding a kennel licence.

The Western Dog Association appoints someone locally as a contact person for each breed and needs to keep their names and telephone numbers on file.

Each pedigree dog registered with the NDA has a unique pedigree dog identifier—dog#. Data such as the dog’s two names, date of birth and gender need to be recorded. A dog has only one registered owner with the NDA at any one time and the NDA wishes to record this but does not need to keep records of a dog’s prior owners.

Membership
Owners pay subscription fees to belong to the NDA and thus the Western Dog Association. These are processed through the NDA’s Melbourne office which allocates them a membership#. One membership subscription covers any number of pedigreed dogs the member might own. Periodically, the NDA sends the Western Dog Association a list of paid-up members, including their names, addresses and phone numbers and the details of the pedigree dogs registered to them. The Western Dog Association office uses this list to update their records.

Obedience Training Classes
The Western Dog Association sponsors dog-training classes. The Association keeps names and addresses of trainers who conduct obedience classes for dogs. Only paid-up Association members may enrol their dogs in these classes. Trainers run weekly classes at various time and locations around the state and the Association keeps track of enrolments of dogs in these classes. Unfortunately, due to a scarcity of qualified trainers, dogs may only be enrolled in one class at a time.

Each class has a unique ClassID. The Association only keeps records of the current obedience class enrolments. It has no need to be able to look up past enrolments. Any breed of pedigree dogs can take part in these obedience classes but many of the dogs are German Shepherds. Owners who want to enrol their dog in an obedience class first contact the Association. They want to know the cost, and where and when the classes are held. They also need a telephone number to contact the appropriate trainer.

(a) Complete the entity relationship diagram (ERD) that represents a design for a relational database to satisfy the needs of the Western Dog Association. Include two extra entities ‘Owner’ and ‘Breed’ and name any relationships they might have. Include the attributes of the ‘Dog’, ‘Owner’ and ‘Breed’ entities on your diagram. Underline Primary keys. Foreign keys show links to other entities (tables). Draw a ring around any foreign keys in your design. (1 page available) (9 marks)

(b) Give two examples of non-primary key attributes in the Class table that could benefit from an index and explain why. (6 lines) (3 marks)

(c) Describe how you would change the database design as it stands at the moment to allow the Association to efficiently answer inquiries from owners who want to know if there is room in a particular class for their dog. Classes are restricted to enrol a maximum of 30 dogs. (4 lines) (2 marks)

(d) The Association has been approached by the Police to allow non-pedigree dogs to enrol in their obedience classes. The Committee has decided that this would be an excellent form of community service and is prepared to find extra trainers but does not want to have the expense of changing the design of the database to allow this. They would expect owners of non-pedigreed dogs to become paid-up members of the Association. How would you include training of non-pedigree dogs without changing the design of your database? (6 lines) (3 marks)

(e) With the extension of obedience classes to community members, many existing Association members have asked if they can now enrol their dogs in more than one class. Extra trainers have been employed to conduct obedience classes so this should now be possible. The current database makes no allowance for this. Which of the following three design changes is the most suitable to implement in a relational database to solve the new requirement? You must explain your choice to obtain credit. (6 lines) (2 marks)

Question 33 [14 marks]

The Firbank City High School has a large number of students. In their final year these students study a limited number of subjects. The school intends to offer prizes to the best and second best student in each subject, and a special prize for the best student overall. Subject prizes are awarded for the highest marks in the year. The best student prize is awarded to the student who was awarded the greatest number of prizes for being best in a subject. For each subject, the data is stored on a sequential file, the records of which contain the student name and mark.

The mainline for the program has been written by someone else, and is shown in pseudocode below.

FOR each subject

FindTopTwo(subject-file, first_student, second_student)

OUTPUT “First prize goes to: ” first_student

OUTPUT “Second prize to:” second_student

ADD first_student to top_student_array

ENDFOR

FindBestStudent(top_student_array, top_student)

OUTPUT “Overall prize awarded to: ” top_student

(a) Draw a diagram showing how the mainline program (above) and the two modules will interact. Show clearly which parameters are passed to and from the modules. (half a page) (4 marks)

(b) Write an implementation using pseudocode for the module FindTopTwo. This module is required to determine the best and second best students in a subject, given the data file for that subject. You are permitted to read the file ONLY ONCE. You may make the following assumptions:

• There are at least three records on the file.
• No two student marks are the same. (24 lines, i.e., one page) (10 marks)