3 Sensing data and turning it into something usable
3.2 Human beings, data, signs and symbols
We live in a sea of sensation: sight, sound, touch, taste, smell and balance (really a sense of our bodies in three-dimensional space). These sensations, and our ability mentally to process, and then react to and communicate them, are vital to our survival. What we perceive with our senses we call the most primitive form of data: perceptual data.
However, as Example 1 showed, human beings don't just react instinctively; they respond reflectively, using thought. In other words, we seek to name, to classify and finally to understand what we perceive. A reaction like withdrawing your hand from something that is painful to touch is instinctive. Physiologically, such a reaction protects us from harm.
Language, one of the defining characteristics of human beings, is a hugely complex system of meaningful sounds which can be combined and repeated. It enables us not only to name and classify our sensations, but also to communicate them and our thoughts about them to others.
About 30,000 years ago human beings began making ‘useless’ objects: items not strictly necessary for survival. They couldn't be used as tools, eaten or used to keep warm. They were the beginnings of art. These ‘art’ objects were often marked with regular scratches, rhythmic lines or dots. No one now knows what these marks meant to the people who made them. Yet we believe that they were signs conveying specific meanings to those who made and used them (anything from counts of days between full moons to reminders of important events in the stories told around the communal fire at night).
A sign (or symbol: we consider these terms to have the same meaning in this unit) can be defined as something that conveys some information by means other than direct representation. Signs represent something other than themselves: they symbolise something. Signs vary: a beeping sound at a light-controlled pedestrian crossing symbolises that it's safe to cross while the beeping continues, an arrow on a traffic sign symbolises the way to go when it's not obvious (In this unit the terms ‘sign’ and ‘symbol’ are considered to have the same meaning). In the well-known painting, the Arnolfini Double Portrait by Jan van Eyck (shown in Figure 1), the inclusion of the dog in the foreground symbolises domestic fidelity, and the convex mirror in the background symbolises the observing eye of God, keeping watch over the couple.
Figure 1 The Arnolfini Double Portrait by Jan van Eyck (1434) portrays the marriage of Giovanni Arnolfini and Giovanna Cenami, and is rich in Christian symbolism (National Gallery)
The painting includes many other objects which are symbolic as well as representational, such as the shoes, the single candle in the candelabra, and the positions of the couple's hands.
Generally, we distinguish signs and symbols from representations by saying that:
they have a meaning apart from their direct representation;
this meaning is understood by a group of people who agree broadly on what that meaning is.
A flag symbolises a nation or other group, and what is pictured on the flag usually symbolises things important to that group: homeland, language, history or myth. The hands of the couple in Figure 1 symbolise a very ancient custom that the groom ‘asks for the hand’ of his future wife, and the bride ‘gives her hand in marriage’.
Coming back to language, words are also signs. The word ‘cow’ symbolises a particular type of ruminant animal from which we get milk, meat, and sometimes muscle power. The word itself is not a cow; neither is it a particular cow (‘Daisy’); it symbolises the animal we think of as a cow.
Figure 2 From a map by Olaus Magnus, Swedish cartographer, 1539
Exercise 6
Would you call the item shown in Figure 2, and which appears on antique maps, a sign in the sense used above? If so, what does it symbolise?
Now read the discussion
Discussion
It is intended to be a sign that symbolises a coniferous forest on the map (you may have said woods, trees or something similar). Note that most maps have a legend which explains the exact meaning of such signs, although they are intended to be easy to interpret.
Signs can be of many types. There are visual signs (such as road signs), audible signs (beeps and tones used as attention-getters or warnings) and tactile signs (such as textured paving stones near a road crossing).
Exercise 7
Can you think of any other examples of tactile signs? What might their uses be?
Now read the discussion
Discussion
You might have thought of braille, which is intended to be read by those with a visual impairment using the tips of the fingers.
Even for sighted users, tactile signs can be useful. Where the user must use sight or hearing for other things (operating complex machinery), or where vision or hearing is not possible (in very dark or very noisy environments), the position, shape, size or texture of a tactile sign can ensure that the user knows what it is without having to look at it. Most cars, for example, use position to differentiate between two otherwise similar controls such as the indicator lever and the windscreen wiper lever.
An alphabet of touch
Louis Braille, the inventor of the braille system, was only a precocious 10-year-old when he entered Valentin Haüy's pioneering school for children with a visual impairment in 1819. Haüy – a specialist in decoding manuscripts before he founded the school – had already invented a form of writing for people with a visual impairment using an embossed alphabet. Though a great step forward, Haüy's system had its drawbacks: it was prone to errors and confusion.
When Braille was 12, Charles Barbier de la Serre, a French army captain, visited the school and described his system of 12 raised dots representing sounds which could be combined to form words. Braille experimented with Barbier's system and, by the time he was 20, he had simplified it so that each letter of the alphabet could be represented by six raised dots arranged in three rows.
The dots are precisely placed in relation to each other for each character and precisely aligned (sloppily written braille is even harder to read than messy handwriting), and the 63 combinations of dots and positions comprise an alphabet, numerals, the main mathematical signs and a music notation.
Braille is interesting because the basic unit of the sign is, simply, the raised dot, whereas most alphabets compose letters using straight lines, dots, curves and compound marks. Thus braille is very simple and purely abstract (that is, it has no remnants of an iconic system, such as representing the quantity zero by an empty circle). An average braille reader can read about 150 words a minute.
The braille system also freed those with a visual impairment to write for themselves (using a variety of hand- and machine-operated tools). Nowadays computers can produce braille text directly.
In summary, a sign or symbol is a way of representing data. For example, the word ‘blue’ is a sign of a particular colour sensation; a seemingly-simple word like ‘cow’ is a sign of a complex thought or idea derived from many sensations; a road sign can represent some condition of the road (e.g. that it narrows ahead) and warn the driver to take care.
SAQ 1
Describe in your own words what is meant by a sign or symbol, and explain how your personal name is an example.
Now read the answer
Answer to SAQ 1
You might have said something like this: a sign is a representation of something, where the representation could be a sound (such as a word) or a drawing or some other more abstract representation. To be a meaningful sign, there must be a group of people who agree on what the sign represents.
My name is a sign in that it is not me, but represents me to myself and to others (e.g. my family, my employers, my community).
Thursday, April 22, 2010
An introduction to data and information
3 Sensing data and turning it into something usable
3.1 Making sensation make sense
In the previous section you learned something about what data is, where it can be found, and how it can be used. But have you ever thought about how we get data in the first place? As human beings, we are so used to reading, writing, speaking and observing that we rarely think about the true origins of the data we commonly use with such ease. I don't intend taking you back to these origins – that would take too long. Rather, I want to describe how human beings ‘get’ data and put it into a useful form.
This section aims to:
provide a more detailed definition of data;
show in simple terms how human beings can turn sensory data into something that can be communicated and reasoned about.
Before computers, it was mainly philosophers who thought about how human sensation (such as sight or hearing) could be turned into an abstract thing like thought (i.e. ideas or reasoning). To do this, most agreed, sensation had somehow to be transformed into an appropriate form. Once it had such a form, it could become the subject of thought, and human beings could reason about it.
Example 1
If you touch a surface, one of the things you will sense is its temperature, i.e. whether it is hot, cold or neither. This is a survival mechanism: if a surface is so hot, or so cold, that it will damage your hand, you need to remove it immediately. But between the extremes of damagingly hot or cold there are all sorts of other sensory experiences: uncomfortably hot, comfortably hot, comfortably warm, neutral, comfortably cool, and uncomfortably cold. Even these categories can be further divided.
If we were only able to react instinctively to our sensations of hot and cold, we wouldn't be able to convey anything about that surface to another person – for instance to warn them that the surface was damagingly hot or cold. So in the course of our evolution, we have developed the means of transforming sensation into a form that can be thought about and communicated. We have developed words like ‘hot’, ‘cold’, ‘warm’, and ‘cool’. Such words allow us to link one sensation (touch) to another (vision) (e.g. ‘as hot as burning coals’) and use them to convey our thoughts to other human beings who share our language.
But humans have also gone further. Languages have been given written form, which enables us to transmit our sensations and thoughts across time and space, so that someone over four centuries ago could write:
as, the icy fang
And churlish chiding of the winter's wind,
Which, when it bites and blows upon my body,
Even till I shrink with cold, I smile …
(Shakespeare, As You Like It)
and convey to us now the feeling of coldness.
Also, because science doesn't deal in words (such as ‘cold’) which are open to different interpretations, we have developed more objective measures of hot and cold, such as the length of a column of mercury in a thermometer. Thermometers can then be used to compare temperatures by dividing the column of mercury into gradations, called degrees Celsius (written °C). (I n some countries temperature is measured in degrees Fahrenheit.) So everyone will agree that a particular surface with a temperature of 112°C is hotter than one of 91°C, even though both may feel unbearably hot.
The remainder of this section looks at the concept of sensation, and how perceptions of sensation (such as feeling something is warm or seeing colour or hearing sounds) can be represented so that a computer can do something with them.
3.1 Making sensation make sense
In the previous section you learned something about what data is, where it can be found, and how it can be used. But have you ever thought about how we get data in the first place? As human beings, we are so used to reading, writing, speaking and observing that we rarely think about the true origins of the data we commonly use with such ease. I don't intend taking you back to these origins – that would take too long. Rather, I want to describe how human beings ‘get’ data and put it into a useful form.
This section aims to:
provide a more detailed definition of data;
show in simple terms how human beings can turn sensory data into something that can be communicated and reasoned about.
Before computers, it was mainly philosophers who thought about how human sensation (such as sight or hearing) could be turned into an abstract thing like thought (i.e. ideas or reasoning). To do this, most agreed, sensation had somehow to be transformed into an appropriate form. Once it had such a form, it could become the subject of thought, and human beings could reason about it.
Example 1
If you touch a surface, one of the things you will sense is its temperature, i.e. whether it is hot, cold or neither. This is a survival mechanism: if a surface is so hot, or so cold, that it will damage your hand, you need to remove it immediately. But between the extremes of damagingly hot or cold there are all sorts of other sensory experiences: uncomfortably hot, comfortably hot, comfortably warm, neutral, comfortably cool, and uncomfortably cold. Even these categories can be further divided.
If we were only able to react instinctively to our sensations of hot and cold, we wouldn't be able to convey anything about that surface to another person – for instance to warn them that the surface was damagingly hot or cold. So in the course of our evolution, we have developed the means of transforming sensation into a form that can be thought about and communicated. We have developed words like ‘hot’, ‘cold’, ‘warm’, and ‘cool’. Such words allow us to link one sensation (touch) to another (vision) (e.g. ‘as hot as burning coals’) and use them to convey our thoughts to other human beings who share our language.
But humans have also gone further. Languages have been given written form, which enables us to transmit our sensations and thoughts across time and space, so that someone over four centuries ago could write:
as, the icy fang
And churlish chiding of the winter's wind,
Which, when it bites and blows upon my body,
Even till I shrink with cold, I smile …
(Shakespeare, As You Like It)
and convey to us now the feeling of coldness.
Also, because science doesn't deal in words (such as ‘cold’) which are open to different interpretations, we have developed more objective measures of hot and cold, such as the length of a column of mercury in a thermometer. Thermometers can then be used to compare temperatures by dividing the column of mercury into gradations, called degrees Celsius (written °C). (I n some countries temperature is measured in degrees Fahrenheit.) So everyone will agree that a particular surface with a temperature of 112°C is hotter than one of 91°C, even though both may feel unbearably hot.
The remainder of this section looks at the concept of sensation, and how perceptions of sensation (such as feeling something is warm or seeing colour or hearing sounds) can be represented so that a computer can do something with them.
An introduction to data and information
2 Daily life and computers
2.3 Summary
This section showed that computers pervade our daily lives, but that many of them are invisible to us.
It investigated the information requirements of certain individuals, such as shoppers and doctors. You learned that their requirements can range from the simple and obvious to the complex and not so obvious.
You also learned that it is not just individuals who require information: it is also essential to the operation of organisations. The example of loyalty cards was used to demonstrate how the data associated with such cards could be used to derive information that could be put to subtle use.
The section also provided simple definitions of data and information, and noted that these will be developed further in this unit.
2.3 Summary
This section showed that computers pervade our daily lives, but that many of them are invisible to us.
It investigated the information requirements of certain individuals, such as shoppers and doctors. You learned that their requirements can range from the simple and obvious to the complex and not so obvious.
You also learned that it is not just individuals who require information: it is also essential to the operation of organisations. The example of loyalty cards was used to demonstrate how the data associated with such cards could be used to derive information that could be put to subtle use.
The section also provided simple definitions of data and information, and noted that these will be developed further in this unit.
An introduction to data and information
2 Daily life and computers
2.2 The organisation: loyalty cards
Many supermarkets and other firms (such as petrol companies and airlines) use loyalty cards: cards that offer a customer some form of incentive, such as a future discount or gift, to continue buying from that firm. For example, the British supermarket chain Tesco issues such cards. The holder of a loyalty card is regularly sent vouchers which give the holder discounts from their shopping bills and also vouchers which enable them to gain a discount on items that the supermarket wishes to promote.
When applying for a loyalty card you are required to fill in a form which asks for your name and address, and possibly details about your lifestyle, such as what sort of car you drive, your annual salary range, and so on.
Once you have your loyalty card, it will be swiped through a reader whenever you take your purchases to the check-out.
This subsection is concerned with how a supermarket, or any other organisation, uses the data:
taken from the loyalty card application form;
generated when the loyalty card is swiped through the reader at the check-out.
Exercise 5
Can you think of a use for the postcode data that is written on the loyalty card application form of a supermarket chain?
Now read the discussion
Discussion
You might have said that it is used to send special offers to card holders, and that's correct. However, the senior management of the supermarket chain might use postcode data in a much more subtle way. They often open new branches, and your postcode is a valuable piece of data which helps them to anticipate what the effect might be of opening a new branch in a particular area.
When a loyalty card is swiped at the check-out, the data associated with the holder is linked to the set of products which the holder has just bought. This provides further information for the senior management of the supermarket chain. For example, it could be used to detect whether there is any pattern in the buying habits of customers. If, for example, one product is consistently bought with another (e.g. bottled beer with snacks) this could lead the supermarket chain to display the linked items together in the aisles or near to the check-out in the hope of increasing sales
2.2 The organisation: loyalty cards
Many supermarkets and other firms (such as petrol companies and airlines) use loyalty cards: cards that offer a customer some form of incentive, such as a future discount or gift, to continue buying from that firm. For example, the British supermarket chain Tesco issues such cards. The holder of a loyalty card is regularly sent vouchers which give the holder discounts from their shopping bills and also vouchers which enable them to gain a discount on items that the supermarket wishes to promote.
When applying for a loyalty card you are required to fill in a form which asks for your name and address, and possibly details about your lifestyle, such as what sort of car you drive, your annual salary range, and so on.
Once you have your loyalty card, it will be swiped through a reader whenever you take your purchases to the check-out.
This subsection is concerned with how a supermarket, or any other organisation, uses the data:
taken from the loyalty card application form;
generated when the loyalty card is swiped through the reader at the check-out.
Exercise 5
Can you think of a use for the postcode data that is written on the loyalty card application form of a supermarket chain?
Now read the discussion
Discussion
You might have said that it is used to send special offers to card holders, and that's correct. However, the senior management of the supermarket chain might use postcode data in a much more subtle way. They often open new branches, and your postcode is a valuable piece of data which helps them to anticipate what the effect might be of opening a new branch in a particular area.
When a loyalty card is swiped at the check-out, the data associated with the holder is linked to the set of products which the holder has just bought. This provides further information for the senior management of the supermarket chain. For example, it could be used to detect whether there is any pattern in the buying habits of customers. If, for example, one product is consistently bought with another (e.g. bottled beer with snacks) this could lead the supermarket chain to display the linked items together in the aisles or near to the check-out in the hope of increasing sales
An introduction to data and information
2 Daily life and computers
2.1 The individual: an average day
If I take an average day in my life, I find myself surrounded by computers, most of which are invisible to me. This section looks at where computers are found in the course of everyday life. It aims to:
place computers in the context of the activities we do and the things we handle in our day-to-day lives.
But it does this from two points of view: the individual and the commercial organisation.
A day in my life
I wake to a radio-alarm. It's controlled by a small computer that lets me set the time I want to wake up and the radio programme that will wake me.
I prepare breakfast on a cooker which has a small computer that controls the clock, timer, and other functions such as oven temperature.
I take my dog for a walk. She has a ‘microchip’ (i.e. a very small simple computer) implanted under her skin that will enable her to be traced if she is lost or stolen.
I take my son to his nursery in the car. It has a number of small computers that control the steering, manage the engine, and control the braking system.
My son's nursery has a computer that children as young as two can use. The nursery keeps its records on a computer and it has a website.
At work, I write material such as this unit using a computer, and find information both from the library catalogues and from the World Wide Web (the web) using my computer. I send and receive emails from colleagues down the corridor or across the world.
During my lunch break I stop at the bank. My computer-produced statement has a confusing entry that I want clarified. On the way out I draw cash from another computer (an automated teller machine or ATM).
I phone a friend using my mobile telephone. It's controlled by a small computer, and my network is able to locate my phone and connect my calls through computer-controlled switching systems.
After picking up my son, I drive to the supermarket. Supermarkets are just one form of business that depends on computers to check stock, order items that are running out and add up sales, among other things. These computers also use my loyalty card to record my preferences, and issue me with vouchers that might entice me to Exercise these preferences.
On the way home I pass a police speed camera. If I were exceeding the speed limit, its computer-controlled system would recognise my number plates, identify me as the owner using the DVLC licensing records, and automatically send me a ticket. (Of course, it's not triggered into action as I pass by!)
Later in the evening my partner and I go to visit a friend who's in hospital. Because we aren't too sure where the hospital is, we use an in-car navigation system to help us get there using the best route.
At the very end of the day, I take a shower which uses a small computer to control the temperature and pressure to ensure I'm neither frozen nor scalded if someone else in the house turns a tap on or off.
The one thing I'm fairly certain of is that my bed doesn't (yet) contain a computer.
Exercise 2
Think about your day as I have thought about mine. Note down the places you visit and things you do in the course of the day, and tick those items you think involve a computer of some kind. As you study this unit, you may want to return to this list to check whether you were right about computers being involved.
Now read the discussion
Discussion
Chances are, if you've chosen an ordinary day, you'll do many of the same things I described above. Many, if not most, of these will involve a computer in some form or other. Most modern mechanical devices are now controlled entirely or partially by computers, including buses, trains and aircraft. Even bicycles are sometimes fitted with a computerised speedometer and odometer.
Most activities these days involve exchanging data or finding and using information – tasks that increasingly are being done by computer.
Exercise 3
Imagine wandering around your local supermarket. Mentally observe the behaviour of other shoppers and the staff at the supermarket. Write down the information that these two groups need.
Now read the discussion
Discussion
There is no single answer to this Exercise. I can only give you some examples.
Shoppers want information about a particular product, where it is, what it costs and perhaps nutritional information associated with the product.
The store manager wants different information, such as:
which items are being sold quickly so that shelves can be replenished and stock reordered;
what the daily turnover of the supermarket is so that new staff can be hired when business increases.
The staff who stack the shelves need to know what products to put on shelves, and where the products can be found.
Staff at the check-outs need to know what some products are (e.g. different fruits, or how to distinguish pastry items) in order to enter the correct codes.
Exercise 4
What sort of information would a doctor need in the course of his or her working day?
Now read the discussion
Discussion
Here is my list of the things I believe a doctor needs to know:
personal information about a patient which enables the doctor to visit that patient;
the patient's medical records which show previous treatments, any adverse reactions to treatments, and so on;
information about the external bodies that deal with patients, such as the location of the nearest pathology laboratory, and the name of the consultants at the local hospital who treat particular disorders;
information about the latest policies and procedures of the NHS;
recent research findings relevant to a patient's condition.
The above list shows how daunting information requirements can be. A doctor needs everything from the simple and obvious (the patient's name and address) to the complex and possibly obscure (the latest research findings on a rare disease).
Data and information
So far, I have used two words in connection with computers: data and information. Did you see any differences in the way the two terms have been used? Let me point out one.
Data refers to discrete items, such as the price of an item on the shelf of a supermarket, or the type of product listed on a sign over a supermarket aisle. The word ‘data’ is a plural Latin word but it is generally used as a singular word in English.
In contrast, information involves linking together two or more items of data to provide an item of knowledge. If someone suddenly said to you, ‘50p’, you'd be a bit puzzled. However, being told, ‘The price of a litre of milk is 50p’, would convey information. In other words, information can be thought of as the answer to a question such as: ‘What is the price of this product?’ So the words ‘50p’ said in connection with nothing would mean little, but stated in answer to the above question would convey information or knowledge.
It's true that the distinction I've made here between data and information may seem fuzzy. One person's data could be another's information (as you will see later in this unit). But for now, please work with the simple definitions given above.
2.1 The individual: an average day
If I take an average day in my life, I find myself surrounded by computers, most of which are invisible to me. This section looks at where computers are found in the course of everyday life. It aims to:
place computers in the context of the activities we do and the things we handle in our day-to-day lives.
But it does this from two points of view: the individual and the commercial organisation.
A day in my life
I wake to a radio-alarm. It's controlled by a small computer that lets me set the time I want to wake up and the radio programme that will wake me.
I prepare breakfast on a cooker which has a small computer that controls the clock, timer, and other functions such as oven temperature.
I take my dog for a walk. She has a ‘microchip’ (i.e. a very small simple computer) implanted under her skin that will enable her to be traced if she is lost or stolen.
I take my son to his nursery in the car. It has a number of small computers that control the steering, manage the engine, and control the braking system.
My son's nursery has a computer that children as young as two can use. The nursery keeps its records on a computer and it has a website.
At work, I write material such as this unit using a computer, and find information both from the library catalogues and from the World Wide Web (the web) using my computer. I send and receive emails from colleagues down the corridor or across the world.
During my lunch break I stop at the bank. My computer-produced statement has a confusing entry that I want clarified. On the way out I draw cash from another computer (an automated teller machine or ATM).
I phone a friend using my mobile telephone. It's controlled by a small computer, and my network is able to locate my phone and connect my calls through computer-controlled switching systems.
After picking up my son, I drive to the supermarket. Supermarkets are just one form of business that depends on computers to check stock, order items that are running out and add up sales, among other things. These computers also use my loyalty card to record my preferences, and issue me with vouchers that might entice me to Exercise these preferences.
On the way home I pass a police speed camera. If I were exceeding the speed limit, its computer-controlled system would recognise my number plates, identify me as the owner using the DVLC licensing records, and automatically send me a ticket. (Of course, it's not triggered into action as I pass by!)
Later in the evening my partner and I go to visit a friend who's in hospital. Because we aren't too sure where the hospital is, we use an in-car navigation system to help us get there using the best route.
At the very end of the day, I take a shower which uses a small computer to control the temperature and pressure to ensure I'm neither frozen nor scalded if someone else in the house turns a tap on or off.
The one thing I'm fairly certain of is that my bed doesn't (yet) contain a computer.
Exercise 2
Think about your day as I have thought about mine. Note down the places you visit and things you do in the course of the day, and tick those items you think involve a computer of some kind. As you study this unit, you may want to return to this list to check whether you were right about computers being involved.
Now read the discussion
Discussion
Chances are, if you've chosen an ordinary day, you'll do many of the same things I described above. Many, if not most, of these will involve a computer in some form or other. Most modern mechanical devices are now controlled entirely or partially by computers, including buses, trains and aircraft. Even bicycles are sometimes fitted with a computerised speedometer and odometer.
Most activities these days involve exchanging data or finding and using information – tasks that increasingly are being done by computer.
Exercise 3
Imagine wandering around your local supermarket. Mentally observe the behaviour of other shoppers and the staff at the supermarket. Write down the information that these two groups need.
Now read the discussion
Discussion
There is no single answer to this Exercise. I can only give you some examples.
Shoppers want information about a particular product, where it is, what it costs and perhaps nutritional information associated with the product.
The store manager wants different information, such as:
which items are being sold quickly so that shelves can be replenished and stock reordered;
what the daily turnover of the supermarket is so that new staff can be hired when business increases.
The staff who stack the shelves need to know what products to put on shelves, and where the products can be found.
Staff at the check-outs need to know what some products are (e.g. different fruits, or how to distinguish pastry items) in order to enter the correct codes.
Exercise 4
What sort of information would a doctor need in the course of his or her working day?
Now read the discussion
Discussion
Here is my list of the things I believe a doctor needs to know:
personal information about a patient which enables the doctor to visit that patient;
the patient's medical records which show previous treatments, any adverse reactions to treatments, and so on;
information about the external bodies that deal with patients, such as the location of the nearest pathology laboratory, and the name of the consultants at the local hospital who treat particular disorders;
information about the latest policies and procedures of the NHS;
recent research findings relevant to a patient's condition.
The above list shows how daunting information requirements can be. A doctor needs everything from the simple and obvious (the patient's name and address) to the complex and possibly obscure (the latest research findings on a rare disease).
Data and information
So far, I have used two words in connection with computers: data and information. Did you see any differences in the way the two terms have been used? Let me point out one.
Data refers to discrete items, such as the price of an item on the shelf of a supermarket, or the type of product listed on a sign over a supermarket aisle. The word ‘data’ is a plural Latin word but it is generally used as a singular word in English.
In contrast, information involves linking together two or more items of data to provide an item of knowledge. If someone suddenly said to you, ‘50p’, you'd be a bit puzzled. However, being told, ‘The price of a litre of milk is 50p’, would convey information. In other words, information can be thought of as the answer to a question such as: ‘What is the price of this product?’ So the words ‘50p’ said in connection with nothing would mean little, but stated in answer to the above question would convey information or knowledge.
It's true that the distinction I've made here between data and information may seem fuzzy. One person's data could be another's information (as you will see later in this unit). But for now, please work with the simple definitions given above.
An introduction to data and information
1 An introduction to data and information
1.3 Summary
This section briefly discussed the public awareness of computers and how quickly this has developed from a situation where computers hardly impacted on most people to one where they are involved in virtually every facet of modern life. As an illustration, you examined the contents of your wallet to determine how much data about you (your persona) might be kept by a variety of organisations. This sets the scene for developing an understanding of how this affects you as an individual in modern society.
The aims of the unit were then described.
1.3 Summary
This section briefly discussed the public awareness of computers and how quickly this has developed from a situation where computers hardly impacted on most people to one where they are involved in virtually every facet of modern life. As an illustration, you examined the contents of your wallet to determine how much data about you (your persona) might be kept by a variety of organisations. This sets the scene for developing an understanding of how this affects you as an individual in modern society.
The aims of the unit were then described.
An introduction to data and information
1 An introduction to data and information
1.2 Aims of the unit
This unit will:
use case studies (real-life examples of interesting aspects of the unit which illustrate particular points) that relate the use of computers to finding, storing, processing and disseminating data and information;
describe various instances of computer use to see how computers can work with data to produce information;
introduce you to what a browswer is, and how to use one;
demonstrate how to use a search engine to find information more effectively.
1.2 Aims of the unit
This unit will:
use case studies (real-life examples of interesting aspects of the unit which illustrate particular points) that relate the use of computers to finding, storing, processing and disseminating data and information;
describe various instances of computer use to see how computers can work with data to produce information;
introduce you to what a browswer is, and how to use one;
demonstrate how to use a search engine to find information more effectively.
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