OCR AS ICT G061 - All Chapters
- Created by: AmyBabe17x
- Created on: 11-04-15 15:44
Chapter 1 – Data, Information, Knowledge and Processing
Data
Raw facts and figures, unprocessed, no meaning e.g. 3553vdvdb
Information
Taking data and processing it, based on certainties Pe.g.
Information = Data (23042015), structure(23/04/2015), context (UK date), meaning (my birthday)
Representation Methods
Text
Adv: explanations, clear, read if noisy
Dis: language, long explanations, need to see
Pictures
Adv: no language, always there, ok if noisy
Dis: need to know signs, no explanations
LED
Adv: cheap, power efficient, little memory
Dis: meaningless, close to see them
Video
Adv: explanations, how to… videos
Dis: time consuming, hearing and visual, linear
Animation
Adv: convey actions, language dependant
Dis: only shows steps, no sound
Sound
Adv: grab attention, visual impairments, area
Dis: hearing, everybody hears, be there at time
Knowledge
Application of information to give understanding
Knowledge can change, add more information, based on rules
Knowledge base – what someone knows
Data Types
Boolean – one of two values e.g. Y/N, true/false, gender
Real – numbers with decimals e.g. 47.65, currency
Integer – whole numbers e.g. 54, number of people
String – alphanumeric characters e.g. hello, house number, telephone number
Date/Time – numbers and letters e.g. 07/06/2015, birthday
Static and Dynamic Data
Static doesn’t change, dynamic can change
Static
Dynamic
Limited information
Large volume of data
No internet access
Need internet access
More reliable
Not always reliable
Not updated quickly
Data updated quickly
Need the book/CD
Access anywhere
Data Sources
Direct data collected for purpose and by you e.g. mobile phone usage
Advantages
Disadvantages
Correct data
Costly to collect
Trusted source
Time to collect
Small sample size
Indirect data for different purpose, different org using data e.g. mobile phone info to catch criminals
Advantages
Disadvantages
Instantly available
Not meet requirements
Sources compared
Out of date
Large sample sizes
Unreliable
Not detailed
Quality of Information
Accuracy, relevance, age, completeness, presentation, level of detail
Encoding Data
Replacing data with shorter data e.g. January = Jan
Purpose – speed up processing, reduce storage, improve accuracy, improve presentation, security
Advantages – storage, processing speed, quick input, validation, presentation, confidentiality
Disadvantages – interpretation, accuracy, completeness, limited codes, value judgements
Validation
Purpose – ensure data is sensible, reasonable, in acceptable boundaries, complete
Process – data within boundaries, process during data input, reduce data entry errors
Range check – within a range e.g. date before today
Type check – data conforms to particular data type e.g. real
Length check – specific length e.g. 5 chars
Picture check – has a pattern e.g. XX99
Presence check – data exists e.g. cannot be NULL
Lookup check – data exists in a list e.g. M or F
Check digit – extra digit from calculation of original data
UPC check digit – ((odd numbers positions x 3) + even numbers positions) / 10 = 10 – remainder
ISBN check digit – the digit goes into the table, add results of multiply row, divide by 11, the remainder is subtracted from 11, if answer is 10 use X
Digit
0
2
0
1
3
5
3
…
Comments
No comments have yet been made