Heinemann Information Processes and Technology: HSC Course

The answers below are, in many cases, only a brief guide to a full answer. Some of the answers in the learning activities have not been provided as they involve the student investigating, forming opinions, working in a group or completing practical tasks on the computer.

Chapter 2: Information systems and databases

Exercise 2.1

1Information systems perform a set of information processes requiring participants, data/information and information technology. They are created to provide access to information for an organisation or individual.

2Five types of information systems are transaction processing systems (TPS), decision support systems (DSS), expert systems, management information systems (MIS) and office automation systems.

3Batch processing collects the transaction data into a group and processes it later. It has a time delay, and this may be a significant disadvantage. In real-time processing, each transaction is immediately processed. It provides instant confirmation of a transaction but does require access to an online database.

4A DSS depends on the accuracy of the mathematical model and the ability of the manager to formulate appropriate questions.

5Expert systems are useful in diagnosis, monitoring, selecting, designing, predicting and training.

6The knowledge base is a set of general facts and if-then rules supplied by an expert.

7An MIS presents information about the performance of the organisation, such as reports on sales, stock inventory, payroll, orders and budgets.

8Office automation systems provide people with effective ways to complete administrative tasks in an organisation. They use a range of software tools, such as word processors, spreadsheets, databases, desktop publishing and presentation programs, and project management and communication software.

9aThe purpose of MovieTime Video is to hire videos and sell associated products.

bParticipants―manager and staff. Data/information―member data, video data, barcodes, receipt. Information technology―personal computer, barcode reader, database.

cThe membership data consists of last name, first name, address, phone number, age, sex, date of birth, and work number.

dThe video data consists of an identity number, a title, main stars, a rating, and an entertainment category.

eThe information processes include:

Collecting―scanning the video barcode.
Organising―searching the database for membership details.
Analysing―determining the type of information required.
Storing and retrieving―saving the database to a disk.
Processing―updating the data after it has been entered.
Transmitting and receiving―transferring the data between peripheral devices.
Displaying―obtaining a report on a member’s transactions.

Learning activities

1The effect of information systems include banking (ATMs, plastic cards), learning (Internet, educational software), communication (Internet, email, voice mail), shops (EFTPOS, barcode readers) and individual productivity (PCs, word processing, databases). Student opinion.

2Student opinion. Managers could provide staff with comprehensive guidelines and structures on formatting documents, organising data and surfing the web. Bonuses could be provided for staff that complete a particular task within a timeframe. Performance of staff could be more closely supervised to ensure time is not wasted.

3These issues indicate that expert systems are used in areas where the cost of the expert system is low compared with the expense of paying an expert. Expert systems are commonly used in medicine and the stock market. Expert systems would not be used in any area where experts are paid small amounts of money and are readily available.

4Example of an information system that students regularly use is EFTPOS. A possible DFD would contain.

Process―buying a product.
External entities―customer, sales assistant.
Data flow―product, plastic card, receipt.
Data store―database.

5The ethical issue raise by this situation is privacy. The staff does not have the right to sell the personal data of the members. Student opinion.

Exercise 2.2

1Computer-based databases have several advantages over non-computer databases:

Easily edited―data can be corrected and updated without having to retype all the data.
Large storage―data is stored on a disk and retrieved when required.
Fast find―data is searched and sorted quickly and accurately to obtain the required information.
Display options―data is presented in a variety of ways using tables, forms and reports to suit most purposes.

2Flat file databases organise data using data structures called files, records, fields, and characters:

A file is a block of data.
A record is a collection of facts about one specific entry in a database.
A field is a specific category of data in a database.
A character is the smallest unit of data that people can handle.

3A primary key is a single key or compound key that must have a value. Primary keys cannot be empty or null. A secondary key is a field that contains useful items of data often used in searches. Secondary keys are not always unique.

4A relational database organises data using a series of related tables.

5A schema is the data definition for a database. It is an organised plan of the entire database showing how and where the data is found, descriptions of the data and its logical relationships.

6Entities are related in three ways: one-to-one, one-to-many and many-to-many.

7Data modelling is the process of identifying entities, the relationships between those entities and the attributes of those entities.

8A data dictionary contains information about the characteristics of each item entered in the database, such as the field names, field sizes, data types and field descriptions.

9The purpose of normalisation is to result in a database that is more efficient. The database is unambiguous and as intended.

10A linkis the highlighted text (usually an underlined word or graphic) that allows an electronic connection. If another computer is the destination of the link, that computer is called a node.

11The three parts of the URL are the:

Protocol―the transfer method used to access a particular resource on the Internet.
Domain name―the address of the specific computer where the resource is located.
File path―the full path to the file to be retrieved.

12A storyboardis a series of frames, each representing a different action or screen image. It is a tool used for organising hypermedia.

13HTML (Hypertext Markup Language) is a set of special instructions that indicate how parts of a document will be displayed and navigated.

14Links are achieved using HTML’s hypertext-related tag. It is <A> and stands for anchor. The document to be linked is specified using the instruction HREF="filename". The filename refers to the location or path of the link. After the hypertext reference, the text that will provide the link is specified.

Learning activities

1Three non-computer databases are:

Card file―organises data by sorting cards into logical groups or alphabetically. Data is stored on the cards. Individuals and a range of organisations use card files. Advantages―inexpensive, convenient and easy to secure. Disadvantages―data not easily used for other purposes, difficult to manage for a large amount of data, need to continually sort data, and data is difficult to find if incorrectly stored.
Filing cabinet―organises data into folders usually sorted into logical groups or alphabetically. Data is stored using pieces of paper. Individuals and most organisations have filing cabinets. Advantages include that it is inexpensive, convenient, easy to secure, and if accurately organised provides quick access to data. Disadvantages―data is not easily used for other purposes, difficult to manage for a large amount of data, need to continually sort data, data is difficult to find if incorrectly stored, and finding a physical space for the filing cabinet.
Address book―organises data alphabetically according to the person’s family name. Data is stored using pieces of paper in the book. Individual and community phone directories make use of address books. Advantages include that it is inexpensive, convenient and easy to construct. Disadvantages―data is not easily used for other purposes and difficult to manage for a large amount of data.

2Students could describe boxes, folders, cupboards, bookcases, desk drawers, filing cabinets or books. Student answers depend on the structure of the non-computer database they are using at home.

3A possible schematic diagram for a library would contain:

Entities―Borrower (LastName, FirstName, Address, PhoneNo, BorrowerID), Book (Title, Author, YearOfPublication, ISBN, Reserve, CallNo) and Transaction (DateBorrowed, BorrowerID, CallNo).
Relationships―Borrower to Transaction is one-to-many, Book to Transaction is one-to-many.

4aThe primary key for each entity would be:

Customers―CustomerID.
Seats―SeatNumber.
Events―EventID.

Each of these attributes would have a value and be unique.

bData dictionary needs to be created for each entity (customers, seats and events) using the given attributes. The data type for most attributes is text with the exception of ‘Deposit’ (currency) and ‘Date and Time’ (date). Students should accurately describe each attribute and specify a realistic field size.

cThe schematic diagram would contain:

Entities―Customer (CustomerID, LastName, FirstName, Address, Suburb, PostCode, Deposit and CreditCard), Seats (SeatNumber, Event and CustomerID) and Events (Event, EventTitle, Date and Time).
Relationships―Customer to Event is one-to-many, Seats to Event is one to many.

dData entry form should be designed using appropriate headings and groupings of attributes.

5aThe attribute that is redundant is ‘DateLastGift’ and ‘GiftDate’. The same data is stored in different attributes.

bThe data structure would be modified by replacing the ‘Address’ attribute with attributes called ‘Street’, ‘Suburb’ and ‘PostCode’.

cThe primary key for each entity would be:

Person―PersonID.
Gift―GiftID.

dA data dictionary needs to be created for each entity (person and gift) using the given attributes. The data type for most attributes is text with the exception of ‘AmountToDate’ (currency), ‘DateLastGift (date) and GiftAmount (currency). Students should accurately describe each attribute and specify a realistic field size.

eA schematic diagram would contain:

Entities―Person (PersonID, LastName, FirstName, Address, AmountToDate, and DateLastGift) and Gifts ( GiftID, PersonID and GiftAmount).
Relationships―Person to Gift is one-to-many.

6Students need to create a storyboard with each frame representing a Web page. A frame representing the Web page would then provide a simple linear path. The hypertext document could be constructed using a software package such as PowerPoint.

Exercise 2.3

1A database contains the data and the DBMS accesses this data.

2Data is accessed by referring to the index and obtaining the exact location of the data. Indexed access requires additional time to search the index, as well as processing time for maintenance of the index.

3A distributed database is a database located at more than one site. It acts as a single collection of data but is geographically dispersed.

4Some of the storage media used by information systems include:

Hard disk is a magnetic disk made of metal or glass and covered with magnetic material.
Optical disc is a polycarbonate plastic disk whose surface is covered with a reflective layer of metal. There are many kinds of optical discs, such as CD-ROM and DVD.
Removable cartridge is a hard disk, encased in a metal or plastic cartridge, that can be removed like a floppy disk. There are two common types of removable cartridges: Zip disks and Jaz disks.
Magnetic tape is a very long, thin strip of plastic, coated with a thin layer of magnetic material.

5Public key encryption is a common asymmetric encryption system. It involves a public key that is widely available and a private key that is kept secret. Both keys are developed using complicated number theory. The public key is used to encrypt the message before it is transmitted, and the private key is used to decrypt the message when it is received.

6A backup is a copy of the data that could be used to rebuild the system. A DBMS creates a backup at a specified time. If the system goes down, the recovery process rebuilds the system. It uses the last completed backup and a journal listing all the actions completed by the DBMS since the last backup.

7Sorting is the process of arranging data in a particular order. Searching is the process of examining the database to retrieve data.

8QBE (query by example) is a common method for describing a query. It requires the user to enter the criteria against a field.

9Four keywords used in SQL are:

SELECT―the data to be displayed.
FROM―the source of the data.
WHERE―the query.
ORDER BY―the order in which the results are to be displayed.

10A search engine’s index is built by regularly scanning the Web for new sites and accepting submissions from Web page authors.

11A search engine that offers directories contains lists of Web sites organised into categories, such as technology, entertainment, or sport.

12A search robot is a program that accesses Web sites and gathers information for search engine indexes.

13aAll records whose class starts with 12.

bAll records whose postcode has as the first three numbers 261.

cAll records whose last name starts with the letter ‘H’.

dAll records whose assessment is greater than 60.

eAll records whose first name is ‘Peter’ and suburb is ‘Mossman’.

fAll records whose colour is ‘Red’ and cost is greater than $500.

gAll records whose last name is ‘Tran’ or postcode is ‘2534’.

hAll records whose street number is 9 or price is less than $500.

14aYear = ‘12’ AND Sex = ‘M’.

bSuburb = ‘Auburn’ OR suburb = ‘Lidcombe’.

cSex = ‘F" AND Age <= 18.

dOwe > $10 000 AND Month = ‘July’.

15a6.

b17 (default secondary sort on StudentID).

cMelissa Mullins.

d6 (sorts first digit of address attribute).

Learning activities

1This question requires students to create a relational database with a filename of SMALL BUS. There are three entities: Bus, Patron and Job. Teachers need to assess students’ skills when completing each task.

2aThe query displays the attributes FirstName and LastName using the Employee and Wage entities. It finds all the records whose department is ‘Sport’ and weekly pay is greater than ‘1000’. The result of the query is sorted by family name in ascending order.

bThe query displays the attribute EmployeeID using the Employee and Wage entities. It finds all the records whose suburb is ‘Cabramatta’ and pay date is 31/07/01. The result of the query is sorted by last name in descending order.

cSQL query:

SELECT FirstName, LastName

FROM Employee, Wage

WHERE Employee.Department = ‘Office’ AND (Employee.Suburb = ‘Ryde’ OR Employee.Suburb = ‘Hunters Hill’)

ORDER BY LastName

dSQL query:

SELECT FirstName, LastName, Address, Suburb, PostCode

FROM Employee, Wage

WHERE Employee.WeeklyTax < $50 AND Employee.PayDate = 12/08/01

ORDER BY LastName

eThis question requires students to create a relational database with a filename of RETAIL. Teachers need to assess students’ skills when completing this task.

3Student investigation.

4Student investigation.

Exercise 2.4

1A report is the formatted and organised presentation of data.

2Examples of reports are mailing labels, invoices, sales summaries and telephone lists.

3Reports are often based on a query as the user needs to select the required records to be presented. For example, you may not need a mailing label for everybody in the School database.

4Most DBMS have the following sections in a report: report header, page header, details section, page footer and report footer.

5A report header appears once at the beginning of a report. A page header displays information needed at the top of every page. A page header appears after the report header on the first page of the report.

6A report footer usually displays such items as report totals.

7aThe purpose of the RTA to ensure vehicles are safe, protect road users and provide individuals with a driver’s licence.

bParticipants―manager, staff, IT personnel; data/information―owner data, pink slip, green slip; information technology―terminals, central computer, database.

cData in the registration table would include plate number, expiry date, last name, first name, street, suburb, postcode, year, make, model, shape, chassis number and engine number.

dData in the driver’s licence table would include licence number, first name, middle name, last name, address, suburb, post code, home phone, work phone, birth date, expiry date, donor and photograph.

eThe information processes at the RTA include:

Collecting―entering data from pink and green slips.
Organising―searching the database for owner details.
Analysing―determining the type of information required.
Storing and retrieving―saving and backing up the database.
Processing―updating the information in the database.
Transmitting and receiving―transferring the data between terminals and the central computer.
Displaying―printing details on the registration form.

Learning activities

1This question requires students to create a relational database with a filename of RTA. Teachers need to assess students’ skills when completing each task.

Entities―Driver’s Licence (LicenceNo, Firstname, MiddleName, LastName, Address, Suburb, PostCode, HomePhone, WorkPhone, BirthDate, ExpiryDate, Donor and Photograph), LicenceRego (UserID, LicenceNo, PlateNumber) and Registrations (PlateNumber, ExpiryDate, LastName, FirstName, Street, Suburb, Postcode, Year, Make, Model, Shape, ChassisNumber and EngineNumber).
Relationships―Driver’s Licence to LicenceRego is one-to-many, Registrations to LicenceRego is one-to-many.

2This question requires students to create a relational database with a filename of ST PETERS. Teachers need to assess students’ skills when completing each task.

Exercise 2.5

1An informal source of data is obtained casually during a conversation, meeting or observations. A formal source of data is obtained from a report, a book or an official document. It often provides data that is logically organised.

2To cite an Internet source, include the following information: author’s surname and initial or organisation’s name, title of the complete work or Web page, URL of the page, data of document or Web page publication, and the download date.