Data processing and info

Question 1

What is Data?

Answer 1

Raw data which doesn’t have any meaning
Eg 112048 1209854 2293874
Data can be processed into information

Question 2

What is Information?

Answer 2

Data but with context
Eg 229413 , 396210, 504001
Postal codes for India

Question 3

Direct Data meaning

Answer 3

Data collected for a specific purpose and only used for that purpose

Question 4

Indirect Data meaning

Answer 4

Data obtained from a third party and not used for it orginal purpose

Question 5

Examples of Direct Data sources

Answer 5

Questionnaires (survey)
Interview (talk to people)
Observation (look at people)
Data logging ( uses sensor)

Question 6

Examples of Indirect Data Sources

Answer 6

Electoral Register
Business collecting personal data for use by other third parties

Question 7

Adv of direct data

Answer 7

Original source known so we know reliability (how much sampling bias)
Can gather specific data (obscure data that indirect never measured)
Can gather how much or little data is needed
Up to date data

Question 8

Disadv of direct data

Answer 8

Takes lot of time and money to gather data
May not be able to gather data due to time of the year ( eg summer rainfall data in winter)

Question 9

Indirect data Adv

Answer 9

Immediately available
More likely to have large samples available

Question 10

Indirect data disadv

Answer 10

Irrelevant data will need to be sifted through and deleted
Original source unknown might be unreliable and biased
Might be out of date

Question 11

Factors that affect quality of info

Answer 11

Accuracy
Relevance
Age (how old the data)
Level of detail (can have too much data)
Completeness (eg u only said street not house number)

Question 12

Encryption definition

Answer 12

A way of scrambling data so only authorised people can access it

Question 13

Symmetric Encryption /secret key

Answer 13

Faster but same private key to encrypt and unencrypt

Question 14

Asymmetric Encryption/public key

Answer 14

2 keys
public key used to encrypt data (many can people have)
private key only for receiver to decrypt

Question 15

Types of validation checks

Answer 15

Presence check
Range check
Type check
Length check
Format check
Lookup check
Consistency check
Check digit

Question 16

What is type check

Answer 16

make sure right data type eg
integer
number
alphanumeric

Question 17

What is lookup check

Answer 17

Make sure it matches something in the list
Eg Gender: Male, Female

Question 18

what is consistency check

Answer 18

Make sure data across 2 fields are consistent

Question 19

what is validation

Answer 19

checks when data is input into computer system ensures data is sensible

Question 20

what is verification

Answer 20

process of checking whether data entered into computer matches source

Question 21

2 ways to check accuracy of data

Answer 21

verification
validation
both are needed for accuracy

Question 22

Types of data verification

Answer 22

Visual check
Double data entry
Hash total
Control total
parity check
check sum

Question 23

What is double data entry

Answer 23

Enter data twice compare second to first
like confirm password

Question 24

What is parity check

Answer 24

Checks each byte
Even parity and Odd parity
One bit of data is used as parity rest are used for data

In even parity number of 1’s must be even
1001100
there are 3 ones, so parity will be 1

Question 25

What is check sum

Answer 25

Checks whole file Checks data is transmitted accurately from one device to another Has many algorithms to calculate data is correct

Question 26

What is hash total

Answer 26

Calculation is performed before and after transmitting compares 2 values if same or not same Usually done on large files using data not normally used in calculation eg ID column ( can also do on alphanumeric by converting letter to number)

Question 27

What is control total

Answer 27

same as hash total but only on numeric field this will be a meaningful value

Question 28

Data processing 3 popular types

Answer 28

batch online real time

Question 29

Batch processing

Answer 29

Data is entered together and processed in a large batch called a job done when computer resources are not being fully used usually without human interaction stored sequentially

Question 30

Master and Transaction files

Answer 30

Master File contains important data that doesnt change often Transaction file contains data that changes often Transaction file is validated and then sorted into same order as master then combined

Question 31

Data processing

Answer 31

Data processing turns data into information can be actions like collecting and storage Editing and updating Sorting and searching Outputting and spreading info The word transaction is used for these actions

Question 32

Adv batch processing

Answer 32

automated process so less human error reduces costs fewer tasks for human operator can be scheduled to occur when less resources are used

Question 33

dis batch processing

Answer 33

Delay in data being processed errors can't be corrected until processing is complete only same type of data can be processed since its automated

Question 34

Online processing

Answer 34

Direct access is used ( don't have to go through every previous record to access) processing takes place almost immediately each transaction is processed before the next

Question 35

Examples of online processing

Answer 35

Electronic Funds Transfer (EFT) Online store Automatic stock control Electronic data exchange Business to business buying and selling

Question 36

Real time processing

Answer 36

An example of online processing but response must be immediate usually sensors microprocessors and actuators processing is contiunous eg for sensors in greenhouse temp must be controlled

Question 37

Uses of real time processing

Answer 37

Greenhouse Air-conditioning Computer games

Question 38

adv disadv real time processing

Answer 38

always up to date expensive complex computer system ( high specs)