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Computers And Ict

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image CHAPTER OVERVIEW

Unit 1.1 Information and communication technology
Unit 1.2 Data and information
Unit 1.3 Computers and ICT
Unit 1.4 Types of computers
Unit 1.5 Economic benefits of computers

image At the end of this chapter, you should be able to:

  • Understand ICT systems and how they are used in everyday life.
  • Distinguish between data and information.
  • Give examples of data and information used.
  • Identify the main concepts of a computer.
  • Understand the difference between hardware and software.
  • Describe the information-processing cycle with reference to how it uses hardware devices in each stage.
  • Describe the different types of computers and their uses.
  • Explain the economic reasons for using computers.
  • Understand the different social implications regarding the use of ICT.

INTRODUCTION

We use many different types of computers, or computer-controlled devices every day. This can range from smartphones and calculators, to the scanners used in supermarkets.

The history of computing goes back over 2 500 years to the abacus, which is a simple calculator made from beads and wires, and is still used in some parts of the world today.

In the following units, you will learn more about the different concepts used in computing, the different types of ICT systems used, as well as what the difference is between data and information. You will also look at the various components of a computer and the different types of computers available. Lastly, you will learn about the economic value of computers.

UNIT
1.1   Information and communication technology

ICT SYSTEMS USED IN EVERYDAY LIFE

ICT systems are often confused with computers; however, they are not the same thing. Computers refer to the hardware that forms part of an ICT system. The ICT system refers to the overall set-up, consisting of hardware, software, data and the people that use it. It commonly includes communication technology, such as the internet.

Information and communication technology (ICT) is a field that is related to computers and communication networks. It can also be in the form of audiovisuals, for example, film and digital productions. Digital technologies use data, such as text, numbers, images, sounds and videos. Computers use this data to show information.

In the past, these technologies used to be separate systems, but recently, these technologies have become almost “one”. Computers have become more like smartphones and smartphones have become more like computers. ICT is the field that looks at all these technologies as one.

An ICT system depends on computers, data and people to make the system work. For ICT systems to function correctly, they need to receive, store, retrieve, manipulate and transmit data. Data is often in the form of text, numbers, sounds and images.

EXAMPLE OF AN ICT SYSTEM IN EVERYDAY LIFE

Computers, however, cannot act on their own; a computer needs someone to give it (enter) the data that needs to be processed. To understand how it works, look at the following example.

Supermarkets and chain stores use ICT systems for a variety of reasons. In this example, we will look at the processes of receiving, manipulating, storing and communicating data at a point-of-sale (POS) system.

PROCESSES AT A POS SYSTEM

When you look at a supermarket’s ICT system from the cashier and customer’s point of view, all you see is a stand-alone computer. This computer is called a cash register. However, the cash register consists of much more than that.

All items have a barcode, which is a pattern of narrow and wide stripes that can be read by a barcode reader. The barcode reader is used to scan the barcode optically and convert the stripes into numerical data, which can automatically be transferred to the check-out computer (i.e. the cash register). The barcode reader sometimes beeps after scanning an item to signal to the cashier that the item has been identified.

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Figure 1.1: An example of a barcode
INPUT AND STORING DATA

When an item is scanned, the check-out computer checks for the price of the item in the database. The running total of each item is stored temporarily in the check-out terminal. (There may be other data stored there as well, such as money that was taken out of the till during the day.)

MANIPULATING DATA

After all the items have been scanned, the check-out computer calculates the data to determine the total cost. If the customer pays with cash and requires change, the cashier will enter the amount given and the check-out computer will calculate any change that should be given to the customer. This is an example of the computer receiving data from the user.

TRANSMITTING DATA

When all the items are scanned into the check-out computer, the customer can see information about the price of each item, which is shown on a small display.

After all the items have been scanned, the total amount is shown. The customer then pays and is given a printed till receipt showing all the items that were bought and how much each item costs.

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Figure 1.2: Cash register and receipt
COMMUNICATION

In some instances, a product’s data can also be sent to the shop’s main computer for stocktaking purposes, as well as to the manufacturer for their stock purposes.

image   Activity 1.1

1.Explain the term ICT. Do not just expand on the acronym.

2.What does POS stand for?

3.The following table shows a few activities that take place before check-out. Match these activities with one of the following processes associated with a POS, as seen from the customer’s point of view:

  • Receives
  • Sends
  • Stores
  • Retrieves
  • Manipulates
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4.Imagine a world without ICT systems, or ICT-controlled devices. ICTs have several advantages and disadvantages. Copy and fill in the table below, and list three advantages and disadvantages of ICT systems.

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UNIT
1.2   Data and information

In computing, it is very important to understand the difference between data and information. This section will look at the differences between the two and the importance thereof.

What do you think of first when you hear the word data? What comes to mind is raw material, which refers to something that has not yet been processed. Data needs to be processed before it can become useful. Data can be in the form of text, words, numbers or symbols which, if not put into some type of context, is pretty useless to us.

Information, on the other hand, is data that is processed and formatted in such a way that we can actually use it. Both data and information are important; it is through accurate data collection that people, such as managers, have the necessary information to make informed decisions. Let’s take a look at the following examples of data and information:

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As you can see from this example, the data appears to be a set of random words and numbers. Only after the data has been interpreted, organised and formatted, you can see that it is the contact details for David Mahlangu.

Let’s look at the following example of how data can be converted into useful information.

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Animation

Make an animation similar to what is shown in the following video: https://www.youtube.com/watch?v=Rs57-PQyqaE You can also use baking a cake as example. This example will include the following as data: flour, baking soda, salt, milk, eggs, icing sugar, the oven as the computer and the cake as information.

DETERMINING HOW THE LEARNERS DO IN MATHEMATICS

Mandla’s Mathematics teacher needs to determine how the learners in her class are performing. She must get the test results (data) and the average of each learner, as well as the average mark for the entire class (information).

There are five learners in the Mathematics class and so far, they have written three tests.

Table 1.1: Data about learners’ test results for three tests

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Table 1.2: Maths results Term 1 (sorted from highest to lowest score in percentage)

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Tables 1.1 and 1.2 show the difference between data and information. In Table 1.1, we cannot see how the learners are performing. However, after the computer manipulated the test scores, we are given meaningful information, as can be seen in Table 1.2. Remember, the information we get out of a computer is only as good as the data that is entered into it.

THE GIGO PRINCIPLE

GIGO is an acronym for Garbage In, Garbage Out. Simply put, it means that bad input will result in bad output. It is very important to remember the GIGO principle, because bad data will give you bad information.

Using the example of the learners’ test results, if the teacher entered the incorrect marks into the computer (i.e. bad data), the information that she would get as a result, will also be incorrect.

It is quite possible for data to be interpreted incorrectly. This is often the result of incorrect or incomplete data, or a lack of context.

THE INFORMATION-PROCESSING CYCLE

For you to understand how a computer works, you need to understand the information-processing cycle. The stages in this cycle repeat itself over and over again and is made up of the following:

  • Input: In the first stage of computing, the computer receives some data or instructions to follow.
  • Processing: In the second stage of computing, the computer follows the instructions programmed into it and manipulates the data in some way.
  • Output: In the third stage of computing, the computer supplies the new, manipulated information in some way. This information can be displayed on the screen (for example, the message you see on the screen while you type), or it can be sent to a different part of the computer where it is received as input.
  • Storage: An optional stage is where data is stored. The data can be stored permanently (on a hard drive), or temporarily (on RAM – i.e. the computer’s short-term memory).
  • Communication: Another optional stage is communication, where the output created is sent across a network to other computers. While this step used to be rare in the past, most computer programs perform some type of communication today.

An example of the information-processing cycle is shown in the following figure:

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Figure 1.3: The information-processing cycle

The information-processing cycle is a series of stages carried out to get information from raw data. Although each of the first three stages explained above (input, processing and output) must be taken in order, the order is cyclic. The output stage can lead to the repeat of the data-collection stage, resulting in another cycle of data processing.

image   Activity 1.2

1.Sizwe is in Grade 10 and received his school report. When he looks at his report, this is what he sees:

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1.1 What is wrong with this report?

1.2 Which principle is referred to above?

1.3 Explain the difference between data and information.

1.4 Use the data from the previous page and create a report showing the correct information for Sizwe. Use the table below to guide you:

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2.Answer the following questions based on the scenario below.

Computers are electronic devices that manipulate data and turn it into useful information. To see how this works, think about sending a WhatsApp message from a cell phone to a friend.

The diagram below shows the different stages in sending a WhatsApp message.

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2.1 What process is shown in this diagram?

2.2 List the different stages from A to F.

2.3 What happens during Stage C of this cycle?

2.4 Indicate whether the following is input, output, or storage:

a. Typing a message to a friend on WhatsApp

b. Music that you listen to from your phone

c. Printing a file

d. Playing videos using your phone

e. Photos that you keep on your phone

UNIT
1.3   Computers and ICT

Computers are electronic devices that receive data, manipulate the data and then turn it into useful information, before storing it and/or sending it to someone, or somewhere, to be read or acted upon.

The following figure tries to explain how a computer works. You can see that the functions of a computer are similar to the stages of the information-processing cycle.

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Figure 1.4: General model of a computer

Looking at the figure, you will see that all basic computers consist of four functions:

1. Input

2. Storage

3. Processing

4. Output

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WHAT MAKES A COMPUTER A COMPUTER?

These four things are combined to make a computer work.

For a computer to function properly, it must consist of both hardware and software, which both depend on each other. Without software, the hardware of a computer will have no function and vice versa. Both of these concepts are discussed in detail in the chapters to follow; however, we will just briefly explain what each means.

  • Hardware: The physical components of a computer, also referred to as the equipment of a computer.
  • Software: More commonly known as apps (applications) or programs and consists of a list of instructions in a computer language that instructs the computer on what to do.

Examples of hardware devices consist of the following:

  • Keyboard and mouse used for input
  • Monitors, printers and speakers used for output
  • Hard drives and flash disks used for storage
  • Routers used for communication
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Figure 1.5: Computer hardware

image   Activity 1.3

1. What is a computer?

2. Match each concept in Column A with the correct definition in Column B. Write only the number and the letter.

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3. Answer the questions based on the diagram below.

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3.1 Name the missing stages, as indicated by the letters below:

a. A:

b. B:

c. C:

3.2 List one example of each of the following:

a. Hardware

b. Software

3.3 Your teacher is busy printing out the term class reports. Which stage is this in the information-processing cycle?

4. Complete the following table and identify two hardware devices that your teacher will use for each of the missing stages. Motivate why she would use those specific devices.

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UNIT
1.4   Types of computers

As you know, computers are devices used to process information. There are several terms used to describe computers; most of these terms indicate the size and the capability of the computer. The two main categories of computers are:

1. Multi-purpose: These types of computers have an operating system that can run many applications at the same time. Some examples are devices, such as servers, laptops and smartphones.

2. Dedicated devices: These are devices that can only run one task. Some examples are ATMs and processors embedded in devices, such as refrigerators and motor cars.

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Figure 1.6: Different types of computers

MULTI-PURPOSE DEVICES

Table 1.3: Different types of general-purpose computers

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DEDICATED (EMBEDDED) DEVICES

Embedded devices are devices designed for a single purpose; whether that purpose is to wake you up in the morning, control the temperature of the air conditioning or help navigate. As such, these devices are usually excellent at their specific tasks, but they are also unable to do anything else. Embedded devices are designed to perform specific dedicated computing tasks. Examples of these devices are:

  • ATM machines
  • DVD players
  • Anti-lock braking systems
  • Digital watches
  • MP3 players
  • Drones
  • Airbag control systems

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TYPES OF COMPUTERS

UNIT
1.5   Economic benefits of computers

Over the years, it became impossible to imagine a world without computers or computer-controlled devices, such as ATMs, cameras and music players.

Computers have several economic benefits, such as:

  • Saving paper: Companies and individuals can save paper by working electronically on computers. People can now send letters (emails), magazines and read books electronically instead of having to print out hard copies. This also saves money and time in the long run. Estimates have shown that there can be a 10 to 30% decrease in paper usage if the correct technology is used.
  • Saving labour: Businesses can save money and labour (people) by using computer-controlled devices to perform repetitive functions that require several employees to perform.
  • Communication speed and costs: Telephone and postage costs can be decreased drastically using computers and the internet. It also allows information to be sent and received faster than in the past. For example, the use of email allows instant communication with staff, clients and other individuals at any place or time. The use of smartphones will help employers to keep in touch with their employees regularly, which ultimately saves time and phone calls.
  • Efficiency: Instead of being swamped with paperwork or sorting out piles of paperwork, files can be stored on computers. Retrieval of old documents is much easier when it is stored electronically. Also, computers can do the work of more than one person in less time than normal employees.
  • Accuracy: Computers produce more accurate data or results than human beings. This, however, depends on the quality of the input data. If the information entered is incorrect, the results produced will most likely be incorrect. Computers can, however, detect certain human errors and might highlight these errors.
  • Reliability: Computers that are maintained properly will be reliable in the long run. It is safe to say that we can rely on computers to perform the tasks that they have been programmed to do.

image   Activity 1.4

Read the following scenario and answer the questions that follow.

SAVING PAPER

The largest bank in the USA, Bank of America, greatly reduced its paper consumption by making use of electronic reports and forms, emails, double-sided copying and by using lighter-weight papers. As a result, it saved tonnes of paper, decreasing the consumption by 32%. (This is over a billion sheets of paper!)

a. Give two examples of how computers benefit the economy by saving paper. Motivate your answer.

b. List three ways of how computers have benefited the economy in South Africa. Motivate your answer.

imageCase Study   Thembisile and her smartphone

To understand how dependent we are becoming on smartphones, read the following case study about a day in Thembisile’s life.

This is an example of a smartphone user, Thembisile, and how she uses her phone throughout the day.

Every morning at 07:00, Thembisile is woken up by the alarm on her smartphone. This alarm clock application has a function that plays soft music for five minutes before she has to wake up. This actually prepares her brain to wake up. After that, the tone becomes louder, which she cannot ignore. If she hits the snooze button, her alarm is set to snooze five times for five minutes at a time.

After Thembisile has woken up, she checks her emails, WhatsApp messages, other texts and her social media updates, such as Facebook and Twitter, which were set to not send any messages to her between 21:00 and 07:00.

She then has breakfast, which she logs into her meal plan application. This indicates the number of calories she consumed. She also adds toothpaste and soap to her shopping list application.

Her calendar application shows that she is supposed to be at the gym in 30 minutes. She gets into her car and mounts her phone on the hands-free device attached to the windscreen of her car. She then switches her phone to GPS navigation, which works out the best route to her three calendar appointments, i.e. gym, work and her 13:00 meeting.

At the gym, she uses her gym application and inputs her weight, height and energy level into the application. This gives her an exercise routine she should focus on for the session.

She realises she is running a little late for work, so she sends a quick message to her manager using an instant message service (IMS), such as WhatsApp. Her normal keyboard is replaced by SwiftKey, making it much quicker for her to type.

At work, Thembisile uses a note-taking application to make notes of the things she is currently working on, as well as the scheduling application, which books and shares new appointments. She then uses CamCard to scan the new business card she just received so that the details are automatically saved in her contact list.

Before going to bed, Thembisile quickly looks at the day’s important news events on her news application and plays some of the several games on her phone, such as Pokémon, Candy Crush and Angry Birds.

At 22:00, her sleep application tells her it is time to sleep.

As you can see, Thembisile, and probably her entire family, are very active smartphone users. Information is transferred, stored and conveyed in their everyday lives. This is the direction that the world of technology is moving towards. It also shows us how dependent we are becoming on computers, or computer-operated devices.

Answer the following questions about the case study that you have just read:

1. Give a brief description of a smartphone.

2. Identify four applications that Thembisile uses during the day.

3. From the case study, identify five things for which Thembisile uses her phone. How does this improve her day-to-day life?

4. How does Thembisile’s employer benefit from using a smartphone?

5. How does the SwiftKey keyboard differ from the normal keyboard on a smartphone?

REVISION ACTIVITY

1. Study the picture of a computer below and answer the questions that follow:

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a. Identify and name two input devices. (2)

b. Is device A an input device or an output device? (1)

c. What is the function of device B? (2)

2. Match the user in Column A with the type of computer in Column B.

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     (3)

3. Your school has bought a new computer for the administration office. List two economic benefits of having a computer in the office. Explain how the school benefits in each case. (6)

4. a.   Define what is meant by an embedded device. (2)

b. Give an example of an embedded device that will be found in a motor car. (1)

5. Look at the diagram below and answer the questions that follow:

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a. What stage of the information-processing cycle is taking place at 3? (1)

b. Does stage 6 represent storage or communication? Give a reason for your answer. (2)

6. Your class teacher ticks off each morning who is present at school. At the end of the term, she determines how many times each learner in the class was absent. This number is included in the learner’s term report. Using this scenario, explain the difference between data and information. (4)

TOTAL: [24]

AT THE END OF THE CHAPTER

Use the checklist to make sure that you worked through the following and that you understand it.

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