# KS3 Computing

CS: Computer Science

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CS01: design, use and evaluate computational abstractions that model the state and behaviour of real-world problems and physical systems
KeywordDefinition
abstractionsimplifying some complex details in order to focus on the main points of a problem
computational abstractionusing a computer to make a simplified model of a complex problem
modela simplified version of a complex problem
physical systemsa process or machine such as a car production line or theme park rollercoaster
real world problemsomething that can be difficult to predict or calculate such as the weather or how a disease spreads
simulationusing a computer program to analyse or predict how a physical system or real world problem works
CS02: understand several key algorithms that reflect computational thinking [for example, ones for sorting and searching]
KeywordDefinition
algorithmstep by step instructions to solve a problem
binary searcha searching algorithm which only works if data is sorted in order. It works by repeatedly ignoring half of the data until it homes in on the value it's looking for.
bubble sorta sorting algorithm that goes through a list of data, swapping values where necessary, until each value is in order
computational thinkingusing logical problem solving skills to solve problems
datavalues stored in a computer (e.g. numbers, text, pictures or files)
linear searcha searching algorithm works even if data is not sorted in order. It goes through each value in a list of data in turn, until it finds what it's looking for.
searchingfinding a specific value within a list of data
sortingarranging data in order
CS03: use logical reasoning to compare the utility of alternative algorithms for the same problem
KeywordDefinition
algorithmstep by step instructions to solve a problem
best casethe minimum number of steps an algorithm might need to finish (e.g. if a list has already been sorted)
datavalues stored in a computer (e.g. numbers, text, pictures or files)
logical reasoningcomparing results from different algorithms to decide which is best suited to solve a particular problem with a particular set of data
pre-processingwork done on data in order to get it ready before it's suitable to be used with an algorithm (e.g. sorting before searching)
speedhow many steps an algorithm needs to take before it finishes
worst casethe maximum number of steps an algorithm might need to finish (e.g. if a list doesn't contain the value the algorithm is searching for)
CS04: use a graphical programming language (e.g. scratch) to solve a variety of computational problems
KeywordDefinition
clonea copy of a sprite that allows you to have multiple versions of a sprite which all behave in the same way
costumethe appearance of a sprite that can be changed to make an animation
initialisationthe scripts that run right at the start of the program to make sure variables are set to sensible values and sprites start in the right places
messagedata that gets sent from one sprite to another to trigger something to happen
programming languagea way of describing instructions that a computer needs to understand so that it can run them in order
scripta block of code that describes how a computer can follow an algorithm
spritean object that can be controlled with scripts to change its behaviour
stagethe background object which can't move but can have scripts and constumes
variablesomething that stores some data which might change whilst the program runs
CS05: use a text based programming language (e.g. python) to solve a variety of computational problems
KeywordDefinition
debugfinding and fixing errors in a program
Integrated Development Environmentthe software used to write, run and debug programs
iterationinstructions that cause some lines of code to be repeated multiple times
logic errora type of error message that occurs when your code runs and does exactly what you've told it to do, but you told it to do the wrong thing.
programming languagea way of describing instructions that a computer needs to understand so that it can run them in order
runtime errora type of error message that occurs when your code runs but then crashes because it tries to do something impossible
selectioninstructions that make a choice which lines of code to run next
sequencemore than instruction running in a specific order
syntax errora type of error message that occurs when you break the rules of the programming language. The code refuses to run at all.
CS06: make appropriate use of data structures [for example, lists, tables or arrays]
KeywordDefinition
booleana data type which describes either True or False
data structurea special type of variable which can store more than one value (e.g. a list)
data typewhat sort of value is stored in a variable (e.g text, number or boolean)
identifierthe name of a variable
integera data type which describes a whole number (e.g. 1, 2 or 3 but not 1.34)
lista data structure which can store multiple values in a specific order
naming conventionthe set of rules a programmer should follow when choosing variable names
stringa data type which describes text e.g. "Hello" or "123!"
valuethe data stored inside a variable
variablea named location in memory which can store a value
CS07: design and develop modular programs that use procedures or functions
KeywordDefinition
algorithmstep by step instructions to solve a problem
functiona section of code that has been given a name which can be used more than once in a program in order to calculate and return a value.
identifierthe name of a function or procedure that describes what it does
modulara type of program that has been split up into reusable parts, called procedures and functions
naming conventionthe set of rules a programmer should follow when choosing variable names
procedurea section of code that has been given a name which can be used more than once in a program in order to do something useful.
programlines of program code which follow an algorithm in a way can be run
return valuedata that gets sent back from a function to the part of the code that called it
CS08: understand simple Boolean logic [for example, AND, OR and NOT] and some of its uses in circuits and programming
KeywordDefinition
ANDa way of combining two boolean values where the output is only True if both inputs are also True
booleanTrue or False (or On / Off)
boolean logicmaking a decision based on a True / False (or On / Off) question
circuitselectronic chips which can make decisions based on boolean values
NOTa way of inverting a boolean value so the output is the opposite of the input
ORa way of combining two boolean values where the output is True if either (or both) inputs are True
programmingwriting code that can make decisions based on boolean values
CS09: understand how numbers can be represented in binary, and be able to carry out simple operations on binary numbers [for example, binary addition, and conversion between binary and decimal]
KeywordDefinition
binaryusing 0s and 1s to represent data
bita binary digit which stores a single 0 or 1
bit valuethe amount that each bit is worth when you're working out the decimal value of binary data
byte8 bits, storing a number between 0 and 255
decimalusing the digits 0-9 to represent data
least significant bitthe bit on the right of a binary value (always worth 1)
most significant bitthe bit on the left of a binary value (worth 128 for an 8 bit number)
nibble4 bits, storing a number between 0 and 15
overflowsomething that happens when you haven't got enough bits to store a large number
CS10: understand the hardware and software components that make up computer systems, and how they communicate with one another and with other systems
KeywordDefinition
central processing unitthe hardware component that executes instructions to process data
desktop publishera type of software that lets you design documents to be printed (e.g. booklets / newsletters)
file managera type of software that lets you move, copy or rename files
graphics editora type of software that lets you edit / create pictures
hard disk driveslow, secondary storage which stores files so that they're kept even when the computer is switched off
hardwarephysical components that make up part of a computer system (e.g. keyboard and CPU)
input devicea hardware component which sends data into the computer from the user (e.g. mouse / keyboard)
operating systemthe software that manages all of the hardware and lets the user run different programs
optical driveDVD, CD or Blu-Ray drive that uses lasers to read / write data
output devicea hardware component which sends data out of the computer back to the user (e.g. printer / screen)
presentation editora type of software that lets you create and display slides
softwareprograms that run on a computer system (e.g. Internet Explorer or Photoshop)
solid state drivefast, secondary storage which stores files so that they're kept even when the computer is switched off
spreadsheeta type of software that lets you analyse data and make calculations
web browsera type of software that lets you browse the Internet
word processora type of software that lets you type and write letters / documents
CS11: understand how instructions are stored and executed within a computer system
KeywordDefinition
addressthe location within memory to read data from or write data to.
central processing unita hardware component which is able to understand and run instructions to control the rest of a computer
computer systemhardware and software working together to process inputs and generate outputs
decodethe second stage of a CPU's job which involves looking at an instruction to work out what it means
executethe third stage of a CPU's job which involves actually doing the current instruction
fetchthe first stage of a CPU's job which involves getting an instruction from memory
instructionslines of code which tell a program what to do
memorya place outside of the CPU which can store lots of values or instructions
registera place within the CPU which can store a single value or instruction
CS12: understand how data of various types (including text, sounds and pictures) can be represented and manipulated digitally, in the form of binary digits
KeywordDefinition
analoguea type of recording which hasn't been converted into binary 1s and 0s
ASCIIa way of represening text where each character in the American alphabet can be represented by a number less than 128
binarya way of representing data that only uses 1s and 0s, which computers can process easily as electronic on / off signals
bitone binary digit (a single 1 or 0)
bitmapa way of representing images by splitting them up into pixels. The colour of each pixel can be described by a number (black & white) or numbers (colour)
charactera single letter or digit that can be used ot make up words or text
digitala type of recording which has been converted into binary 1s and 0s
file sizethe number of bits, bytes, kilobytes or megabytes needed to store a file
picturea type of data where each pixel or shape in a picture can be represented by a number
pixelan individual coloured dot that makes up part of a bitmap image
samplean individual measure of the volume of a sound recording at any moment in time
sounda type of data where each sample of a recording of speech or music and be represented by a number
stringa type of data that consists of zero or more characters to describe text
texta type of data where each character of a written message can be represented by a number
vectora way of representing images by splitting them up into lines and shapes. Each colour and shape can be described by numbers or characters
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