AS Computing Unit 1
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| 23321740 | Computing | The study of natural and artificial information processes | |
| 23321741 | Computation | the process of calculating or determining something by mathematical, logical or interactive methods | |
| 23321742 | Abstraction | How to communicate complex ideas simply and how to decompose problems logically | |
| 23321743 | Automation | turning an algorithm into a computer program | |
| 23321744 | Algorithm | a description, independent of any programming language, of a process that achieves some task. It is a step by step procedure for solving a problem | |
| 23321745 | Sequence | Consecutive steps processed in that order | |
| 23321746 | Assignment | Operation that assigns a value to a variable | |
| 23321747 | Selection | A decision making step | |
| 23321748 | Repititon | Sequence repeated until a condition is met | |
| 23321749 | Dry Run | A step by step simulation on paper showing how an algorithm would be executed recording changing values of variables | |
| 23321750 | Integer | A whole number | |
| 23321751 | Byte | An unsigned integer from 0 to 255 | |
| 23321752 | Real | A number with a fractional part | |
| 23321753 | Boolean | Can be True or False | |
| 23321754 | Character | a single character | |
| 23321755 | String | a sequence of characters | |
| 23321756 | Date/time | Stored as a real number | |
| 23321757 | Enumerated | An ordered set of values | |
| 23321758 | Subrange | range of values within a type eg. capital letters | |
| 23321759 | Set | collection of values of the same type with no order | |
| 23321760 | Record | Data Structure that groups a number of variables | |
| 23321897 | Fixed Value | Initialised without calculation, not changed | |
| 23321898 | Stepper | Steps through a systematic succession of values | |
| 23321899 | Most Recent Holder | Holds the latest value encountered | |
| 23321900 | Most Wanted Holder | Most appropriate value met so far is held | |
| 23321901 | Gatherer | Accumulates the effect of individual values | |
| 23321902 | Transformation | Gets its value from fixed calculation of other variables | |
| 23321903 | Follower | Takes the old value of another variable | |
| 23321904 | Variable | location in memory that contains a data value | |
| 23321905 | identifier | a unqiue name given to a variable / procedure | |
| 23321906 | Global Variable | Declared at start, accessibile anywhere | |
| 23321907 | Local Variable | declared and accessible in one procedure only | |
| 23321908 | Constant | Value does not change throughout program, makes program easier to understand and maintain | |
| 23321909 | Parameter | Value passed into and out of a procedure | |
| 23321910 | Interface | List of parameters when calling a procedure | |
| 23321911 | Call By Value | a copy of the value of the variable used is passed to the procedure | |
| 23321912 | Call By Reference | Procedure accesses (and changes) actual variable used | |
| 23321913 | Array | Ordered Set of values of the same data type, grouped together and referred to by a single identifier | |
| 23321914 | Indices | Are used to refer to individual array elements | |
| 23321915 | Text File | A sequence of printable characters organised line by line | |
| 23321916 | CSV File | Text File, each field of a record is seperated by commas | |
| 23321917 | Binary File | Can include numbers which cannot be displayed in a text editor | |
| 23321918 | Validation | Checking that the data entered is reasonable | |
| 23321919 | Range Check | Value must be within a certain range | |
| 23321920 | Format Check | Value conforms to rules | |
| 23389562 | Length Check | Length of string does not exceed maximum | |
| 23389563 | Type Check | Input as string, try to convert to desired data type eg. integer | |
| 23389564 | Lookup Check | Value has to appear on a known list | |
| 23389565 | Check Digit | Calculated from other digits and appended to code | |
| 23389566 | Prescence Check | Something must be entered | |
| 23389567 | Denary Numbers | Base 10 | |
| 23389568 | Binary Numbers | Base 2 | |
| 23389569 | Hexadecimal | Shorthand for binary, easier for humans to understand | |
| 23389570 | Two's Compliment | Most significant bit is negative | |
| 23389571 | ASCII | uses 7 bits | |
| 23389572 | UNICODE | Uses 16 bits so can represent more symbols than ASCII | |
| 23389573 | Hamming Code | Extra parity bits so can correct error | |
| 23389574 | Single Bit Parity | Reciever checks parity after transmission, Two errors are not detected | |
| 23389575 | Gray Code | Binary representation where consecutive values differ in only 1 bit | |
| 23389576 | Gray Code + | More reliable system & counter consumes less power | |
| 23389577 | Gray Code - | Used in angular movement systems with different clock frequencies | |
| 23389578 | Pixel | The Smallest addressable area in an image | |
| 23389579 | Bitmap | Pixels are mapped to positions in memory that store binary codes for colour of each pixel | |
| 23389580 | Screen Resolution | Numbers of pixels in rows and columns | |
| 23389581 | Image Resolution | Number of pixels per inch | |
| 23389582 | Colour depth | Bits needed to store each pixel | |
| 23389583 | Image File Size | Rows x Columns x Colour Depth | |
| 23389584 | Vector Graphics | Identifies objects that make up an image | |
| 23389585 | Property | Describes size, direction, thickness etc | |
| 23389586 | Drawing List | List of commands that recreate a graphic | |
| 23389743 | Vector Graphic + | Geometric images take up less memory, Scale without distortion & are easier to edit | |
| 23389744 | Data Compression | Reduces the number of bytes used by a file | |
| 23389745 | Run-length encoding | Encode a run of pixels of same colour as 2 bytes storing number of pixels and colour code | |
| 23389746 | Lossy Compression | Discards less important information eg. reduces backgroudn resolution | |
| 23389747 | Analogue Data | Varies in a continous manner | |
| 23389748 | Analogue Signal | Electrical form of analogue data | |
| 23389749 | ADC | Samples analogue signal at regular intervals and converts to a value propotional to amplitude of signal | |
| 23389750 | Nyquist's Theorem | Sample at a frequency atleast twice the rate of the highest frequency in the sample's signal | |
| 23389751 | Synthesised Sound | Digitally generated audio that resembles the human voice or instruments | |
| 23389752 | Testing | Used to reveal the prescence of errors | |
| 23389753 | Black Box testing | Use test data and compare with expected results | |
| 23389754 | White Box Testing | Check each path through the code for errors | |
| 25282566 | Top Down Design | Breaks a problem into smaller problems which are easier to work on | |
| 25282567 | Finite State Machine | Consists of a fixed set of possible states, a set of possible inputs and a set of possible outputs | |
| 25282568 | State Transition Tables | Show the effect on the current state of particular inputs | |
| 25282569 | Pseudocode | A way of expressing an algorithm which uses less strict syntax than a program | |
| 25282570 | Structured English | A way of expressing an algorithm which uses a very restricted subset of language | |
| 25282571 | Structure Table | An indented numbered list of steps produced by stepwise refinement | |
| 25282572 | Hierarchy Chart | Shows levels of subroutines |