Chapter 1 Flashcards
Quality of info
1) Accuracy
2) Age
3) Relevance
4) Level of detail
5) Completeness
ADVANTAGES of coding
- speed of input
- less storage
- presentation
- processing
- validation
- security
- consistency
DISADVANTAGES of coding
- interpretation
- not enough code names
- similarity
- omission
What is data?
Raw facts and figures with no meaning
What is information?
Data with meaning
Name 3 data types
Numeric, Date/Time and character/string
What is the smallest element of an image that can be edited ?
a pixel (picture element)
What is a bitmap graphic ?
Store details about every individual pixel that makes up an image
What is a vector graphic ?
Stores components of the image as mathematical equations.
What is streaming ?
Process that allows video to be viewed straight away without having to wait for the full video to be downloaded
What is a buffer ?
Computer memory used to store a part of the video before it is watched
What does buffering help to do ?
Helps to prevent possible disruptions if there are time delays in streaming while the video is playing
What is the sample rate ?
number of audio sound samples captured per second
What is bit depth ?
The number of bits used for each sound sample
What is bit rate ?
The quantity of data measured in bits that is processed in a given amount of time
How is a sound sample converted from analogue to digital ?
- An ADC will will sample the signal at regular intervals
- samples are the converted to digital format
What is Static Data
data that is either fixed or has to be changed manually by editing a document
What is dynamic data
data that is updated automatically without user intervention
indirect data source
a secondary source that already existed for another purpose
direct data source
a primary source whos data must be used for the same purpose for which it was collected
ADVANTAGES & DISADVANTAGES OF Direct Data Source
data will be relevant
original source is known and trusted
it can take a long time to gather original data
a large sample of statistical data can be difficult to collect for one-off purposes
data is likely to be up to date because it has been collected recently
Bias can be eliminated by asking specific questions
data can be collected and presented in the format required
ADVANTAGES & DISADVANTAGES OF Indirect Data Source
additional data that is not required will exist that may take time to sort through
the original source may not be know and so it ca not be assumed that it is reliable
the data is immediately available
if statistical analysis is required, then there are more likely to be large samples available
data may be out of date because it was collected at a different time
original data may be biased to to its source
data is unlikely to be in the format required
Quality of Information is determined by 5 attributes - name them
ACCURACY RELEVANCE AGE COMPLETENESS LEVEL OF DETAIL
ENCODING vs ENCRYPTION
ENCODED data is stored in a specific format - binary digits (0, 1)
ENCRYPTED data is scrambled so it can not be understood
Symmetric Encryption
oldest method
requires both the sender and recipient to possess the secret encryption and decryption key
Asymmetric encryption
known as public-key cryptography
a public key available to anyone
a private key known only to recipient
the key is the algorithm required to encrypt and decrypt the data
