Learning Objectives / Whāinga Ako

• Define what an "algorithm" is in computational thinking.

• Explain why algorithms are essential for computers and digital devices.

• Identify algorithms in everyday life examples.

• Understand the qualities of a good algorithm (clear, unambiguous, finite).

• Relate algorithms to the concept of a "recipe" for problem-solving.

Getting Started / Whakataki (Prior Knowledge Required)

To get the most out of learning about Algorithms, it's essential to have a clear understanding of:

• Decomposition: Can you break down a complex problem into smaller, manageable parts? (Link to Decomposition page)

• Sequence: Do you understand that the order of instructions is critical for getting the right result? (Link to Sequence page)

Quick Check: Think about how you make your favorite snack. Can you list all the steps in the exact order? If so, you've already thought like an algorithm designer!

What is an Algorithm?

An algorithm (pātuhi) is a set of well-defined, step-by-step instructions for solving a problem or accomplishing a task. Algorithms are the "recipes" or "blueprints" that tell a computer program (or even a human!) exactly what to do and in what order, to achieve a specific outcome. 

• Each step must be perfectly clear, with no room for misinterpretation. A computer cannot "figure out" what you mean if the instructions are vague.

• An algorithm must have a definite end point; it should not run forever.

• It must actually solve the problem it's designed for.

While the word "algorithm" might sound complex, you use algorithms every day!

• A cooking recipe

• Instructions for assembling furniture

• Directions to get to a new place

• The steps you follow to tie your shoelaces

All of these are algorithms because they provide a precise sequence of steps to achieve a specific goal.

How It Works / Me Pēhea te Mahi

Algorithms are central to how digital devices and software & applications function. Every time you use an app, search online, or send a message, an algorithm is working behind the scenes.

The Relationship with Decomposition and Sequence:

• Decomposition helps you break a big problem into smaller, manageable steps.

• Sequence then dictates the precise order of those smaller steps.

• An Algorithm is the complete, ordered list of these decomposed, sequenced steps.

Example: Searching for a Contact on a Phone

Let's look at the algorithm for finding a contact on your phone:

1. START

2. Open the "Contacts" Application.

3. Tap the "Search" icon or bar (Input).

4. Type the first few letters of the contact's name (Input).

5. Wait for the phone to display matching contacts (Phone's CPU runs a search algorithm).

6. If a match is found:

   • Display the contact's information (Output).

7. Else (if no match is found):

   • Display "No contacts found" (Output).

8. END

This is a simple algorithm. More complex algorithms might involve Selection (making choices like "if contact found...") and Iteration (repeating steps like "keep checking until end of contact list").

Assessment / Te Aromatawai

Check your understanding of Algorithms.

1. Multiple Choice: Which of the following is the best definition of an algorithm?

   • a) A type of computer hardware.

   • b) A secret code to protect information.

   • c) A set of clear, step-by-step instructions to solve a problem.

   • d) A computer program that makes a device faster.

2. Short Answer: Why is it important for an algorithm to be "unambiguous" (perfectly clear)?

3. Scenario: You are trying to use an online map application to find directions to a new place.

   • Describe one small algorithm that the map application might follow once you've typed in your destination and clicked "Get Directions."

   • Why is sequence important in this algorithm?

Key Takeaways / Mātauranga

• An algorithm (pātuhi) is a precise, step-by-step set of instructions for problem-solving.

• Algorithms must be clear, unambiguous, and finite.

• Decomposition and Sequence are crucial for creating algorithms.

• Algorithms are the backbone of all computer programs and digital devices.

What's Next?

Now that you understand algorithms as the "recipes" for computers, you're ready to explore how these recipes are translated into working digital solutions and how they become more powerful:

• Computer Program: Learn how algorithms are written using specific Formal Languages to create functional software.

• Selection: Discover how algorithms can make decisions and choose different paths based on conditions.

• Iteration: Explore how algorithms can repeat sets of instructions efficiently to perform repetitive tasks.

• Debugging: Understand how to find and fix errors when an algorithm (or the program based on it) doesn't work as expected.

• Testing: See how systematically checking an algorithm or program ensures it produces the correct results.

• Sorting Algorithms: Dive into specific types of algorithms designed for organizing data.

• Complexity and Tractability: Analyze how the efficiency of an algorithm impacts whether a problem can be solved in a reasonable amount of time.

• Artificial Intelligence (AI): Understand that AI systems are powered by complex algorithms that allow them to learn, reason, and solve problems.

• Big Data: See how algorithms are used to process and analyze massive amounts of data.

• Computer Graphics: Explore how algorithms are used to generate and manipulate visual content.

• Formal Languages: Learn more about the specific rules that define languages used to express algorithms.

• Network Communication Protocols: Understand that protocols are essentially algorithms for how devices communicate.

Continue your journey by clicking on the links to these exciting topics!