1. Data, Information, Knowledge and Processing

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Data

Data

  • A collection of alphanumeric characters without meaning
  • Is meaningless
  • Is a collection of random characters
  • consists of raw facts and fgures before they have been processed
  • E.g. 090909
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Information

Information= Data + Context + Structure + Meaning

Context: taking the data and giving it an environment where our prior knowledge and understanding can make a sense of it

Structure: The presentation of data, including any formatting

Meaning: An understanding of what the data relates to

  • Information is made bt taking the data and processing it
  • Processing is performing some action on the data 
  • This might be sorting, searching or editing 
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Knowledge

Knowledge: Application of information resulting in understanding 

Converting information into knowlege

  • Information is based on certainties 
  • Certainties are things that will occure the same way every time or mean the same thing every time 

Knowledge can change

  •  More information can be added to our knowledge as we add more information we revise our knowledge

INFORMATION= DATA + CONTEXT + STRUCTURE + MEANING

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Use Of Representation Methods

Language: The audience must be able to understand a specific language 

Visibility: Can the audience see information from where they are or are there line of sight issues

Cultural: Are there cultureal differences that mean the words or signs have different meanings 

Complexity of Information: A picture is worth a thousand words but sometimes text can give information 

Attention: Will the audience know the message has been given

Physcial Disability: sight/hearing problems are and issue in transferring information to an audience 

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Representation Methods: Text

Text

Advantages

  • clear to understand lots of detail

Disadvantages 

  • Need to be able to read 
  • Need to understand the language
  • Lots of text cannot be read quickly
  • Directional 
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Representation Methods: Graphics

Graphics

Advantages:

  • Do not need to understand the language to understand the image
  • Can match what you see
  • Many graphics mean the same thing in different countries

DIsadvantages:

  • Can be confusing if you do not understand the symbols used 
  • Directional
  • Not useful for the visually impaired as they cannot see


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Representation Methods: Sound

Sound

Advantages:

  • No fixed position
  • No line of sight required
  • Good for visually impaired people 

Disadvantages:

  • No good in large areas as sound becomes disorted
  • Ususally languahe based 
  • May not know what the sound represents
  • Need to be able to hear
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Representation Methods: Moving Pictures

Moving Pictures

Advantages

  • Lots of information conveyed
  • Not language dependant
  • Can exemplify text

Disadvantages 

  • Linear: if you do not see the beginning you may not understand
  • Problems with sound
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Representation Methods: LED

LED

Advantages:

  • Can allow data to be kept secure
  • Can be used in noisy places
  • Similar graphics

Disadvantages

  • Need to be able to see the lights
  • Combinations of lights may need to be known to be understood
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Data Types

Boolean: Only of two values e.g ( True or False)

Real: Numbers with decimals ( example 47.65)

Integer: Whole numbers e.g. (43)

String: Alphanumeric characters e.g. (Hello World)

Date/Time:  Numbers and letters e.g. (09/06/1960)

Currency: Real becsuse it can hold decimals 

House Number: String because it can contain letters e.g. (3C)

Telephone: String because it had a leading zero and spaces

Gender: Boolean because its a chocie of two e.g. (male or female)

Birthday: Date so it can be calculated and be up to date

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Static Data

Static Data: Remains the same after a refresh

CD-ROM/Magazines

  • Limited amount of information available
  • Does not require access to the internet 
  • More reliable 
  • Cannot be updated very quickly
  • CD can be scratched/broken or the magazine and CD can be lost or stolen 
  • If there are errors, erratum notices would have to be sent out ot people
  • Have to collect/wait for the magazine or CD
  • Magazine does not have sound/multimedia


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Dynamic Data

Dynamic data is data that can change after a refresh, for example websites on the internet 

The Internet

  • The internet has a large volume of information
  • Only people with internet can access the data
  • Information on the internet is not always reliable 
  • Can access through mobile phone and PDA
  • Data can be updated very quickly
  • The internet may not be working
  • Has many different opinions 
  • Available all the time anywhere
  • Internet has a range of multimedia
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Data Sources: Direct & Indirect

Direct

  • No one or thing comes between the source of the data and yourself when collecting the data 
  • No boundaries exists between you and the data 

Indirect

  • Something comes between yourself and the data collection - it might be bought, another person collects it or it is collected for different purposes 
  • Indirect data has two meanings a)someone else collected the data b) the data is processed for a different purpose which it was collected for
  • E.g. collecting data on how many tickets have been sold for a film to make sure it is not over sold, and then using the data to find the most popular film 
  • The people/companies involved in collecting the data are different to those using the data. Typically this might be organisations that conduct market surveys and sell the results to other companies. 
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Advantages and Disadvantages of Direct Data

Advantages: 

  • Source of collection method is known and verified 
  • The exact data required can be collected
  • Can change the data being collected in response to answers 

Disadvantages:

  • May not get a large range of data 
  • Data may not be available depending on time/location 
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Adantages and Disadvantages of Indirect Data

Advantages:

  • Large ranges of data available 
  • Data available from different times and locations
  • Analysis might already been completed on some of the data

Disadvantages:

  • Do not know if any bias was placed on the collection
  • Cannot be certain of accuracy of the recording of data
  • May not have all the information about how, when and where it was collected to make a valued opinion on its usefulness 
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Quality of Information

Accuracy: The information needs to be correct of it is not accurate you cannot rely on it. Of you are asked what day the concert is on and you are given the wrong date. People will miss it 

Relevance: The Information must delete to the topic. Having information that is not relavent increases the volume of data and can take time to look at it. If you are asked who was playing at the concert and were told that the concert is on Monday, it is not relevant. 

Age: Information from the past may not be relavent today. For example, asking where the concert is and being told that last year it was at Wembley 

Completeness: This is only having some of the information. For example, asking when the concert is and being given a date but no time

Level of Detail: The volume of information too much or too little information 

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Encoding Data

Encoding Data: Transfering the data from one format into another. Can include shortining, sympbol replacement or abbreviations

Advantages of Encoding Data

Less memort requiremnt- Storing less information, therefore less memory is required

Security- If the codes are not apparent then it is diffuclt to know and understand the meaning of the codes

Speed of Input- The codes take less time to enter, therefore it is quicker to input a large volume of data

Data Validation- Since the codes follow a strict set of numbers and letters they are easier to validate

Organisation of data- If the data is in a standardised format then it can be compared/organised

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Disadvantages of Encoding

Precision of data is coarsened- e.g. light blue encoded as blue

Encoding of value judgements- "Was the film good?" to be encoded as a judgement of 1-4. This will be encoded by different people and makes comparison difficult

The user needs to know the codes used- If the user does not know the codes they cannot use them

Limited number of codes- If codes are made up of a range of letters and numbers the options will be limited

Diffult to track errors- Validation will ensure the code is entered correctly but the nature of the code will make it difficult to see if the code is actually correct

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Validation

Validation: Is a check that is performed by the computer as the data is being entered. It tries to prevent entry of any data that does not conform to pre set rules.

  • Ensurues the data is reasonalbe, sensible and within boundaries of predefined rules
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Validation Checks

Range Checks

  • Sets an upper and lower boundary for data. The data entered must lie between these two values. For example, secondary school years range up to Yr7-11

Type Checks

  • This makes sure that the data entered is of the correct type. Types include: numeric, string, boolean and date/time

Presence Checks

  • Also called existence checks. NOr every field or question would need to be answered however, there will be some that must have an answer in and be filled in

Length Check

  • When any dat is entered into a computer it has lengths. A single character has a length of 1. Length checks ensure that the maximum and minimum length is achieved by the data entered.
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Validation Checks

Look up Validation: 

  • This looks up the data in another table to ensure that it it valid. It might also return additional information- entering the postcode and house number returns the rest of the address.

Picture Checks: 

  • This is also known as a format check. It checks the data type od each character in each position to check it conforms to rules.

Check Digit:

  • A check digit is calculated using a set of numbers and then added to the end of them. When the code is created, the check digit is created and added to the code. Before the code is processed, the check digit is recalculated and compared within the one in the code. If they're the same, processing continues. If they're not, an error has occured and the code value needs to be re entered.
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Verification

If you have collected some information on paper, at some point it will need to be entered into the computer.

Once you have entered it into the computer you will have two copies. The paper based original and the copy stored in the computer

  • The paper-based copy is known as the source document
  • The copy in the computer is known as the object document

Verification is making sure that the information on the source document is the same as the information on the object document

It does not ensure that the information is correct

There are two main methods of verification

  • Computer verification (double entry)
  • Manual Verification (Proof readin)

The two main errors are transcription and transposition errors. Transcriptions is miscopied. Transcription is where numbers or letters are put in the wrong way 

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Types of Verification Methods

Computer Verification (double entry)

  • Data is entered twice (manually)
  • Computer compares the two sets of data amd if it finds any differences it informs the user
  • If there are any differences, then one of the entries is correct and the other is wrong
  • Double entry method is used by the same person or different people
  • Main problem with double entry is that if the same error is made both times then the computer will not find a difference

Manual Verification (proof reading)

  • Involves the entry on the paper being manually compared with the entry typed into the computer
  • Relies on the person being able to follow two sets of data and find any differences 
  • It is very difficult to keep track of where you are on the paper and where you are working on the screen
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Back Up & Archiving

Backing Up

  • Is keeping a copy of current data, if there is a failure of the computer system, then the back up can be used to restore the data
  • Back up is important so that data is not lost
  • Information is valuable and needs to be protected
  • Once created the back up should not be stored in the same location - it should be on a removable media and taken to another location 

Archiving

  • Is for long term storage of data that us not require immediately
  • Taken off the system and stored in case it is required for an investigation later in the future
  • Data is written to a large capacity storage devices at long intervals
  • Files should be archived when they are no longer needed and when you do not wish to delete them permanently
  • Archiving frees up haed drive space
  • Improves the performance of a system
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Cost of Producing Information

Hardware

  • Used to collect/process/output information
  • Used to store the information to use at a later date 
  • May be necessary for the organisation to purchase items of software
  • On going hardware costs include repair and maintenance costs/upgrades

Software

  • Software needs to be purchased
  • In addition to OS this may include DTP, graphics and website software

Consumables

  • Are items that get used paper/printer/ink/toner/electricity

Personnel

  • Costs related to people working in the organisation
  • People are required to collect/collate/enter/process/output information
  • May also be costs involved in sending people on software training course
  • Costs of covering absences
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