Starting from Scratch

Abstraction - Removing unnecessary detail to help you solve a problem (a computational thinking concept)

Algorithm – an unambiguous procedure or precise step-by-step guide to solve a problem or achieve a particular objective. A set of instructions for achieving a goal or solving a problem.

Block –  a ‘chunk’ of programming or a particular graphic block or piece found in a graphical programming language such as Scratch. Blocks linked together are called a script in Scratch. To find out what a block does, right-click on it, then select help from the pop-up menu.

Blocks Palette – (in Scratch) – the library of blocks in most graphical programming languages.

Command – a step or line of programming.

Coordinate (noun) - Cartesian coordinates are a set of values that show an exact position. In a 2D environment, such as on a graph, two axis are needed, each with an equal number scale. The X axis represents the horizontal position of a point, the Y axis represents the vertical position of a point. Coordinates in a 3D environment require a third axis (Z) which represents depth. Coordinates can be commonly used in coding to position objects (sprites in Scratch) within a program’s visual environment. 

Costume – The costume is the appearance of a sprite on the screen. These are usually editable. A sprite can often have multiple costumes that are changed by programming the sprite.

Debug – to detect and correct the errors in a computer program.

Decomposition - Breaking a problem down into smaller parts (a computational thinking concept)

Execute – to follow a series of instructions. The computer or robot follows the instructions in order to complete the program.

Input – data provided to a computer system, such as via a keyboard, mouse, microphone, camera or physical sensors. Information which is received by the computer from a keyboard, mouse or sensor e.g. pressing the left mouse button or space bar creates an input.

Logical reasoning – a systematic approach to solving problems or deducing information using a set of universally applicable and totally reliable rules.

Output – the information produced by a computer system for its user, typically on a screen, through speakers or on a printer, but possibly though the control of motors in physical systems. Also an action performed by the computer e.g. switching on a light, moving a turtle or sprite across the screen.

Program – A sequence of instructions written to perform a specified task on the computer

Repetition (also known as  ‘Loop’ or ‘Iteration’) – a programming construct in which one or more instructions are repeated, perhaps a certain number of times, until a condition is satisfied or until the program is stopped.

Script – (In Scratch) blocks are snapped together into stacks, called scripts. When you click on a script, Scratch runs the blocks from the top of the script to the bottom. You can program sprites and the stage using scripts.

Selection – ‘when things happen’ - A programming construct in which the instructions that are executed are determined by whether a particular condition is met.

Sequence – to place programming instructions in order, with each executed one after the other.

Sprite – A graphical object that can be controlled by programming.

Stage – (in Scratch) - the Stage is where you see your stories, games, and animations come to life. Sprites move and interact with one another on the Stage. The Stage is 480 units wide and 360 units tall. It is divided into an x-y grid.