1-1 Data, Information and Knowledge

7/28/2019 1-1 Data, Information and Knowledge

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Data, Information &Knowledge


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What is Data?

Data is a stream of raw facts representingthings or events that have happened.In ICT, we usually say that data is made upfrom four basic types:

Numbers

Text Images

Sound


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Storing Data?

Inside the computer, however, all data isstored as numbers: Numbers

Text

Images

Sounds


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Storing Data?

Inside the computer, however, all data isstored as numbers: Numbers are stored as numbers, obviously!

Text characters are stored as a code thatrepresents each e.g. ASCII

Images are stored as numbers representing

the amounts of red, green and blue for eachpixel

Sounds are stored as numbers representingthe loudness at given intervals


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How are the numbers

represented?If you want to store and communicatenumbers electronically, how can you do it? Analogue you could use a range of

voltages, e.g. 5V for the number 5

Digital where the number is

represented in binary form, e.g. thenumber 5 would be stored/sent as 101(using pulses of electricity)


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Number Bases You will be familiar with the decimal

system, and hundreds, tens and units,and a digit from 0-9 in each column

Binary works in a similar way, exceptthat you have units, twos, fours, eights,and each column only contains 0 or 1, e.g.

5 is 101 because its one 4 plus one 1:

128 64 32 16 8 4 2 1

0 0 0 0 0 1 0 1


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Bits and Bytes Each of the 0s and 1s is called a bit

binary digit

Eight bits together form a byte

The longest number a computer canhandle in one go is called a word e.g. a32-bit computer has a 32-bit word length

1024 bytes is a kilobyte, 1024 kilobytes isa megabyte, 1024 megabytes is agigabyte, etc.


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Why Use Binary?

Bits are easy to represent electronically,with 0 being represented by no signal, and1 being represented by a signal

These signals could be pulses ofelectricity, flashes of light even down toindividual photons or electrons

Analogue signals are affected by changingresistance, heat and interference


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Adding MeaningHeres an example of some data:

210769

But what does it mean?


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Adding MeaningHeres an example of some data:

210769

But what does it mean? It's just numbers - it'sraw data!

If I were to add some formatting so that thenumbers read 21/07/69you can see that itbecomes a date. The formatting has addedmeaning!

The meaning might only be clear to a Europeanperson, though - in the USA the date would be

07/21/69and in Japan it would be 69/07/21!


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What is Information? Information is data that has been processed to

make it meaningfuland useful

Data + Meaning = Information

Another way to add meaning is to process thedata. For example, individual exam marks areraw data, but if you were to process those to

say that the average mark for the class was53%, or that boys did better than girls, or that76% of the students in your school got a gradeA or B, then that is information!


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Data or Information?

The number of newspapers sold today

The name of the best-sellingnewspaper

The increase in house prices over thelast year

352098527

Your mark for this weeks assignment

The average mark for the assignment


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Encoding Information

Processing turns data into information

Sometimes you might want to turn

information into data i.e. to store it this is called encoding

How do you code information to make it

easy to re-process, without losing itsmeaning?


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Where is the data from?

Internal or External? Internal communication is communication with people

inside the same organisation or company

External communication is with people outside thecompany, such as suppliers or customers.

Direct or Indirect?

Direct data is collected for the purpose of theprocessing being undertaken e.g. time cards for pay

Indirect data was originally collected for anotherpurpose, but is now being processed to provide extra

information - e.g. spending patterns from credit cards


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Information Channels

Formal or Informal?

Formal channels are the official (or

reliable!) ones, such as memos, letters, thecompany noticeboard, etc.

Informal channels are the unofficial ones,

such as office gossip, informal meetings andrumours these can often be unreliable.


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Good Quality Information

The characteristics of good quality information itshould be:

Accurate

Up-to-date Relevant

Complete

On-time

Appropriately presented

Intelligible


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Collecting Information

How is information about people collected?

1. Obviously you can ask people questions about theirspending habits, etc. (but they might not like it!)

2. Or you can use a more indirect approach: Supermarket loyalty cards

- e.g. easily identify wine-drinking vegetarians!

Credit card transactions- amounts and locations- can help prevent fraud, too!

ATMs, CCTV, till transactions, etc.


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Coding Information

Information stored in a computer is oftencoded

Coding categorises information and can

replace long, description strings with a fewletters or numbers (or both!)

You are probably familiar with examples

such as F for female and M for male


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Coding - Advantages

Information is often coded because:

It is quicker to enter into the computer

It require less disc space to store, and lessmemory to process

It can make processing easier or possible as there will be fewer responses

It improves the consistency of the data asspelling mistakes are less likely

Validation is easier to apply


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Coding - Disadvantages

Coding also has some negative effects :

Information is coarsened by forcing it allinto categories there might not be a

category that matches what you want torecord e.g. hair colour

The same can be true of rounding numbers

the intervals or numbers of categories iscalled the granularity this needs to bechosen carefully to maintain the quality ofthe information


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Knowledge

Data and information deal with facts andfigures

Knowing what to do with them requires

knowledge

Knowledge = information + rules

Rules tell us the likely effect of something

For example: you are more likely to passyour A level IF you do your coursework andrevise for your exam!


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Disadvantages of ICT

What are the drawbacks of using ICT?

Information overloadhaving so much information you cantdo anything with it all!

The systems may be inflexible and not give you theinformation you require

There may be staff resistance to the introduction of ICT

Fewer staff may be required job losses?

Staff become relianton ICT and cant work if the computerfails

Expensive training may be required when systems are updated

Complicated systems or slow hardware may cause stress

The data may be coarsened by coding leading to poor quality

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