Computational Thinking

Definitions

At times in algorithms, there may be a need to select one action out of a set of actions, such as which way to go at a fork in the road. Conditional statements give rules to direct the flow of what happens, such as if something is true, then something will happen or else something else will happen. Conditionals allow a program to make decisions and direct the flow of activities without human intervention.  

Examples

• If it is raining outside then you will need to put on your rain boots, else wear your running shoes.
• If the sensor reads a temperature greater than 25ºC, then show a happy face display, else if the sensor reads a temperature less than 25ºC then show a sad face display.
• If you get to a fork in the maze then turn left else go straight on.
• If (hour < 18:00) {greeting = “Good day”;} else {greeting = “Good evening”:}

Definitions

Computers and other communication systems work with different types of data. Data are values that computers can store and retrieve. Data types are computer language-specific, but they commonly include types such as characters (letters, punctuation, spaces), strings (sequences of characters), integers (whole numbers), fixed and floating point numbers and the Boolean data type, which is often used with conditionals. 

Examples

• Character (e.g., A); String (e.g., Hello!); Integer (e.g., 12)
• Floating-point number (float) (e.g., 15.2203829) - can have a variable number of digits after the decimal
• Boolean (true or false value) - can be understood to mean on/off or start/stop
• If you want to keep track of how many goals were scored, which data type will you use? (integer)
• If you want to store information about whether the light is on or off, which data type will you use? (Boolean)

Definitions

An event involves having one action cause another action, such as how you get a computer to respond to the input of a user. User inputs include actions such as clicking a mouse, tapping a key or touching a screen. 

Examples

• Zooming in on a map when someone clicks on it
• Scrolling through images on a phone when someone swipes the screen
• Adjusting the volume on a video when someone presses the + or - buttons

Definitions

Functions group all the steps of a complex action into one command (e.g., brush teeth). Functions are especially useful for defining a sequence of commands that can be reused, for example how to turn a robot sideways by 90 degrees. The creation of functions is based on pattern recognition, abstraction and logical thinking.

Examples

• Function: Brush Teeth (involves turning on the water, putting toothpaste on toothbrush, etc.)
• Function: Draw a Square (draw a straight line of 3 cm, turn 90º,  draw a straight line of 3 cm , turn 90º, draw a straight line of 3 cm, turn 90º, draw a straight line or 3 cm, turn 90º)
• Function: Header style <h1 style=“color:Gray;”>

Definitions

Input and output (often abbreviated as I/O) is the communication that occurs between humans and computers, computers and other computers, among processes within a computer, or between a computer/robot and its environment. Humans interact with computers using devices called peripherals. When computers interact with other computers it is often over networks such as the internet. I/O occurs at all levels of the computer’s operation.

Examples

• Humans provide input into computers using peripherals such as a keyboard, mouse, webcam, microphone, etc.
• Computers provide output using speakers, a screen, printers, etc.
• Robots use input devices such as sensors (light sensor, temperature sensor, etc.), buttons, etc.
• Robots’ output devices include motors, speakers, actuators, lights, etc.

Definitions

Operators are characters that tell the computer to perform certain mathematical or logic-based actions. The specific operators depend on the programming language but may include operators for adding (+), subtracting (-), multiplying (*), dividing (/), less than (<), greater than (>) and equal to (==), as well as logic-based operations such as AND (&&), OR (II) and NOT (!).  

Examples

• What is the sum of the ages of everyone in your family? (ageMe + ageBrother + ageMom + ageDad)
• Is your brother older then you? (ageBrother > ageMe)
• Greater then and less than return Boolean results (true or false) in most programming languages

Definitions

Repetition involves repeating a step or steps in an algorithm a certain number of times until a certain predetermined end point is reached. Repetitive tasks are very common in computer programing and setting up tasks so that they automatically repeat (loop) can save a lot of time. Loops help programs be more organized and shorter because they cut down on the amount of code that needs to be written.  

Examples

• Explain to someone else the most efficient way of making 100 sandwiches.
• Set up a light to turn on and off at certain times every day.
• Code a car game so that the car will automatically go around the track 10 times.
• Create a piece of art that involves a repeating pattern, like a mosaic tile, mandala, or fractal.

Definitions

The steps in an algorithm always follow a sequence. It should be noted that sequences are rarely linear and may involve tasks which are repeated or only occur under certain conditions.  A flowchart is a good tool for understanding and representing sequences.

Simple, linear sequencing is one of the first concepts learned when coding. 

Examples

• What are the steps you need to do to……? (e.g., change a tire, brush your teeth, make toast). Are there any steps that you repeat?
• Writing out the rules for a game (e.g., what happens first, next, last)
• Describing how you get to school using a map (e.g., where do you start? When do you turn? Where do you end?)
• Explain to someone else how to draw a square of a specific perimeter.

Definitions

Variables are places where you can store and retrieve data. Variables have names that stand in for the data they hold, which makes them an abstract concept since one thing (variable name) represents something else (data). Variables also have a data type (the kind of data that can be stored) and a value (refers to what is stored in the variable). In coding languages, variables are written as case-sensitive single words with no spaces. 

Examples

• var a = 10; var b = 5; a and b are the names of the variables and the = tells you what data is stored in each variable.
• The variable “age” could represent people’s ages (e.g., var age;).
• The variable “rateGrowth” could be used to keep track of a plant’s growth over a certain period of time (e.g., var rateGrowth;).
• The variable “temperature” could be used to store and retrieve the temperature readings from a sensor.
• The variable “StudentName ” could be used to store a student’s name and insert it automatically in a personalized email.

Definitions

In the context of CT, making involves writing code from beginning to end, without using an existing code. This typically comes after familiarity with the language of a coding program and experience with approaches such as tinkering, reusing and remixing. Making aligns with the CREATE phase in the Lee et al. (2011) Use-Modify-Create CT learning progression.

Examples

• Creating an avatar of yourself and drawing it in Scratch
• Designing and building a LEGO™ Mindstorms robot from the various pieces that come in a kit
• Creating and coding a wearable sensor-based device using a micro:bit

Definitions

Reusing means taking pieces of code created by others and using it to solve a problem or meet a need, rather than creating it from scratch. Remixing involves putting together or ‘mashing up’ code for video, sound, text, etc. created by other people to make something new and original.  Reusing and remixing aligns with the MODIFY phase in the Lee et al. (2011) Use-Modify-Create CT learning progression. 

Examples

• Using images available through the Scratch library
• Taking a project that someone else did in Scratch and changing it to make it your own
• Reusing a function that someone else created (e.g., On Start, display temp) 

Definitions

In the context of CT, tinkering is about exploring code in a way that is playful and experimental. Tinkering involves changing things about a code to see what happens using code that someone else has created. Tinkering is important because it develops creative thinking and risk taking. It is also an effective way to begin to learn how a computer code works through cause and effect. Tinkering aligns with the USE phase in the Lee et al. (2011) Use-Modify-Create CT learning progression.

Examples

• Modifying the colours of clothing on a character in Scratch
• Adjusting the code to display your initials on the LED matrix in MakeCode
• Modifying the code for a robot to move in a new way

Definitions

Computational Thinking does not need a computer! Many activities that develop computational thinking can be done “unplugged,” meaning away from computers.  Playing games with rules, doing logic puzzles and creating and following recipes are all ways that Computational Thinking can be done “unplugged.”

Examples

• Paper programming
• Drawing maps or completing mazes
• Playing games where one person tells someone else what to do or where to go
• Completing Truth Table (AKA liar and truth teller) logic games