AS ICT (OCR) G061 3.1.1 Data, Information, Knowledge & Processing lesson slides

September 14, 2009C. Demetriou (2009) 1


û Data is simply raw facts or figuresû Can be made up any alphanumeric

charactersû It has no context û Is has no meaning û e.g.

› 220480› R254RSM› 4009041222453


û Information is data with the addition of Meaning, Context and Structure.

û Information is useful and can be interpreted

û Information is FACT!Information

Data Meaning Context Structure


› 220480ñ 22/04/1980 is a dateñ my date of birth

› R254RSMñ R254 RSM is a car registrationñ Suzuki Swift

› 4009041222453ñ Is a bar codeñ for instant coffee

Meaning

Context


û How do we convey information to one another?› Text› Graphically/Symbols› Pictures/Animation/Videos› Sound› LEDs

û What are the Advantages & Disadvantages of each?


Text

› Take the following statement:"Fruit flies like a banana"

ñ Do small insects prefer a bananañ or does fruit glide through the air in a way similar to a banana


Representation Methods

û Graphically› Numbers are easier to visualise in graphical

formatû Symbols

› Language-independent› Universal recognitionñ Some symbols may have different meanings

so care is neededñ Some symbols are recognised but their

meaning is not so well known.


û What is knowledge?› Knowledge is the result of interpreted

information.ñ “We need more tins of baked beans” might

be the knowledge acquired from interpreting the information given in the stock report.

› Knowledge can be used to setup rules.ñ E.g. “It is hotter in July therefore we will sell

more ice cream, so we need to increase the order for ice cream in June.”


Difference Between Information and Knowledgeû Information is based on factsû Knowledge is based on rules, and these

rules are based on probabilities, not certainties:› “Double clicking an icon in Windows will

open an application”ñ This is not information as it is not a certainty.

› “Icons are pictures”ñ This is information – NOT knowledge


û When data is stored it has to stored in an appropriate type, a data type› Booleanñ Can hold one of two values – True/False, 1/0

› Realñ Holds decimal numbers

› Integer› Stringñ Holds text (can include numbers and symbols)

› Date/Time


û Are you married?û £10.56û Surnameû Wellington Road Southû 0161 958 3132û Smokerû SK1 3UQû VAT Rate


û Original Sourceû Indirect

› Data passed on› Data purchased

û Archiveû Processed Data


Gathered from an original sourceû Collected as part of a transaction in a

shop › e.g Credit Card Number

û Collected in a survey› e.g. Recorded on an OMR form› Recorded in an interview

û Collected using sensors› E.g. weather station


Indirect Source

û Data used for a purpose different to that for which it was originally collected

ñ E.g. a credit card firm uses data about each transaction to bill the customer, then used the data to find out about their spending habits to send them focused adverts.

û Data Passed on/Purchasedñ Junk mail often is sent to people who have

given their details away for another purpose. Could be details used in a competition that have been sold to another company.


û Archive› Data which has been recorded but is old

and has been filed away. ñ Old Student recordsñ Archived footage on the BBC

û Processed data› Data which has been processed can

produce new sets of datañ Sales figures for stores / regionsñ Compiled data for departments


û There is often confusion between a data archive and a backup.

û A classic backup application takes periodic images of active data in order to provide a method of recovering records that have been deleted or destroyed.

û Most backups are retained only for a few days or weeks as later backup images supersede previous versions.


û Essentially, a backup is designed as a short-term insurance policy to facilitate disaster recovery, while an archive is designed to provide ongoing rapid access to decades of business information.

û Archived records can be placed outside the traditional backup cycle for a long period of time, while backup operations protect active data that's changing on a frequent basis.


û Information in ICT can come in two forms› Static (Does not change)ñ Booksñ CD encyclopaediañ Internal Help files

› Dynamic (Changes)ñ Internet Pages


û When would you consider information to be bad quality?

û College Enrolment form› You all filled in an enrolment form› How could the data on the form be of quality?

û What does Stockport College do to ensure the data collected is of good quality?


û Accuracyû Relevanceû Ageû Completenessû Presentationû Level of Detail

Factors affecting quality of information


û It is commonplace to code data.û This is changing the original data into a

shortened version in order to store it in the computer.

û Storing days of the week as Mo, Tu, We etc, or months of the Year as Jan, Feb, Mar…


û Precision of data coarsened› E.g. Light Blue coded as Blue

û The user needs to know the codes utilised› If the user is not aware of the codes then they

cannot interpret the dataû Coding of Value judgements

› E.g. “Did you like the film?” to be coded as a judgement of 1-4. This will be coded differently by different people and makes comparisons difficult.

Problems of Coding Data


û Less storage space requiredû Comparisons are shorted and can

therefore be made quicker, thus speeding up searches

û A limited number of codes exists aiding in validation of input


û Validation ensures that reasonable data is entered into a system, it does not ensure the accuracy of data.


û Range Check› To check that the value entered is within a

pre-determined range. ñ Between 1 and 10 for movie ratings

û Type Check› To check if the data entered is of the correct

data typeñ “66” is not a Surnameñ “Frank” is not a Date of Birth


û Check Digit› Used to see if a number entered is a valid

number using an algorithmñ Credit card numbers are checked in this way

û Length› To check if data entered falls within a certain

size, minimum and maximum.ñ Post codes must be between 5 and 7

characters long (M1 7HR or WC1B 5BE)


û Lookup› Checks to see if the option chosen exists

already on the system or from a pre-determined list, e.g. Male or Female


û Picture or Format check› Makes sure that the data entered follows a

known pattern (e.g. Postcodes, National Insurance Numbers)

û Presence Check› Makes sure that data has been entered into

mandatory fields› Often indicated by an asterisk on a form


û Verification does not ensure the data is correct but that it is entered correctly and reduces errors.


û Double entry with automatic comparison› E-Mail addresses› Passwords

û Problem:› May have made the same error and

therefore it is not picked up


û Proof Reading› Entering data› Reading it back

to check it is correct

û Problem:› Blurred eyes


Information costs money to produce.û Hardware

› To collect, analyse and output the data› Storage space to hold the data› Purchasing of equipment and updating the equipment

û Software› Required to analyse the data and to report on the results› Software licences› Maintenance agreements

û Manpower› People employed to collect or enter the data› Maintenance of hardware and software

û Additional:› Training of staff› User manuals


û Information is used for a variety of purposes:› Decision Making› Planning› Control› Recording Transactions› Measuring Performance

û Intended use affects its value.û Costs must be balanced against the

benefits:› the greater the benefit the higher the cost you

will be prepared to pay.


û Input› Taking data external to the current system and

entering it into the system.û Processing

› Manipulating the data into information – usually into a form understandable by the user

û Output› Taking data within the system and presenting it

to the user, or in a format specified by the user (e.g. on disk)


û Storage› Holding either the input or the results of

processing for use at a later date. û Feedback

› Where the output of the system influences the input.

› There is a continuous loop of input resulting in output which in turn affects the subsequent input.


Input Processing

Storage

Output

Feedback

You need to memorise this diagram as you may be asked to recreate it or apply it in the exam.

Education

AS ICT (OCR) G061 3.1.1 Data, Information, Knowledge & Processing lesson slides