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1.01 Data, information and knowldge
1.02 Sources of data
1.03 Quality of information
1.04 Coding, encoding and encrypting data
Advantages and disadvantages of coding data
3. Speed of Input: data can be input more quickly because only a few numbers or letters need to be input instead of whole words or phrases.
4. Processing: Processors can process data more quickly because they only have to process the coded data instead of the whole word or phrase.
7. Consistency: If the correct codes are used then data will be input consistently without spelling errors, making it easier to be searched or summarized.
2. Interpretation: Codes may be difficult to interpret. For example, with international vehicle registration codes, somebody might look at ET and assume it is Ethiopia or look at S and assume it is Spain. It's even more difficult when considering international dialing codes that are represented by numbers.
4. Efficiently: If a user inputting codes does not know what code to use . then they will not be able to enter the data efficiently. Instead they will have to look up the code.
5. Missing information: It's possible that some information gets lost during the process of coding. For example, if devices on a network are coded as L for laptop, P for printer, D for desktop computer and M for mobile phone, then information about whether or not the mobile phone or laptop is touch screen is lost.
1.05 Checking the accuracy of data
Range check: A range check ensures that data is within a defined range. The following symbols are used are used when comparing with a boundary:
> greater than
< less than
>= greater than or equal to
<= less than or equal to
Verification
Verification is the process of checking that the data entered into the computer system matches the original source.
Visual Checking: A method of verification can be for the user to visually check that the data entered matches the original source.
Double data entry: Another method of verification is to input data into the computer system twice.
Proof Reading
What is Proof Reading?
2.01 Hardware
Input devices are devices that allows data to be entered into a computer system.
Storage medium is the medium on which data is stored.
Internal Hardware Devices
1. Central Processing Unit - The central processing unit (CPU) is the brain of a computer. It is part of the computer that carries out calculations, executes instructions and processes data. It includes the arithmetic logic unit (ALU) and control unit (CU).
4. Read-only memory - Read-only memory (ROM) is memory that, once it has been written to, can no longer be changed. It is permanent and it is non-volatile, which means that when there is no power to the computer, the contents of the ROM will be retained.
Tip: In a computer, there is usually some ROM that stores the instructions to boot (start) the computer.
7. Hard disk drive - A hard disk drive (HDD) is the most common form of secondary storage for the computer due to its relatively low cost per MB (megabyte). The hard disk drive consists of two main parts: the device that is the electronics which store the data, and the disk that is the medium onto which the data is stored.
External Hardware Devices
1. Cloud - Cloud computing is a term that refers to anything where computing services are hosted over the internet and not in the same physical location as the computer being used.
Examples of cloud storage for personal use include:
>OneDrive
>Google Drive
>Dropbox
>Box
