Progression in KS3/4 Algorithms MONDAY 30 TH NOVEMBER SUE SENTANCE

Starter task: Algorithms Take a plain piece of paper Follow the instructions on the next slide in sequence The instructions will generate a picture

Instructions 1. Draw a diagonal line 2. Draw another diagonal line connected to the top of the first one 3. Draw a straight line from the point where the diagonal lines meet 4. Draw a horizontal line over the straight line 5. At the bottom of the straight line, draw a curvy line 6. Draw a diagonal line from the bottom of the first diagonal to the straight line 7. Draw a diagonal line from the bottom of the second diagonal to the straight line 8. What object have you drawn? CSInside – “Algorithm Development” activity

Following on from this exercise …  Write the instructions for a shape of your choice  Make them as clear as possible (Advanced students – use functions for parts of the shape that repeat, e.g. repeat steps 1 – 4 3 times)  Pass the instructions to another student in the room  They follow your instructions  Did your instructions work?

Learning objectives  You will start to understand what concepts and terminology are used in the area of algorithmic thinking in KS3 and KS4  You will develop an understanding of how children develop understanding of algorithms, using the progression pathway document, particularly  You will be able to plan lessons which demonstrate some progression in algorithmic thinking

Menu TimeTopic 9:30Starter: Kite Activity 09:45What do we need to teach Breaking down skills around algorithms How to develop algorithmic thinking 10:15Task: Paper cup activity 10:45Break 11:15Progression pathways 11:30Development of two lesson outlines 12:00SSA Lit Review Q & A 12:30Finish

What do we need to teach?

KS1,2 and 3 - Algorithms KS1  understand what algorithms are; how they are implemented as programs on digital devices; and that programs execute by following precise and unambiguous instructions KS2  use logical reasoning to explain how some simple algorithms work and to detect and correct errors in algorithms and programs KS3  understand several key algorithms that reflect computational thinking [for example, ones for sorting and searching]; use logical reasoning to compare the utility of alternative algorithms for the same problem

Algorithmic thinking at GCSE (OCR) Candidates should be able to:  (a) understand algorithms (written in pseudocode or flow diagram), explain what they do, and correct or complete them  (b) produce algorithms in pseudocode or flow diagrams to solve problems. Candidates should be able to:  (g) understand and use sequence in an algorithm  (h) understand and use selection in an algorithm (IF and CASE statements)  (i) understand and use iteration in an algorithm (FOR, WHILE and REPEAT loops).

AQA GCSE (Algorithms) Students should:  understand that algorithms are computational solutions that always finish and return an answer  be able to interpret simple algorithms to deduce their function  be able to create algorithms to solve simple problems  be able to detect and correct errors in simple algorithms.

EdExcel GCSE (Algorithms) Overall aim no 1 Understanding of what algorithms are what they are used for how they work and the ability to interpret, amend and create algorithms.

EdExcel GCSE (Algorithms)  Understand what an algorithm is, what algorithms are used for and be able to interpret algorithms [flowcharts, pseudocode, structured English, written descriptions, program code]*  Be able to create an algorithm to solve a particular problem, making use of programming constructs [sequence, selection, repetition] and using an appropriate notation [flowchart, written description, program code]  Be able to describe the purpose of a given algorithm and explain how a simple algorithm works  Be able to identify the correct output of an algorithm for a given set of data

EdExcel GCSE - Algorithms (contd)  Be able to identify and correct errors in algorithms  Be able to code an algorithm into a high-level language  Understand how the choice of algorithm is influenced by the data structure and data values that need t be manipulated  Understand how standard algorithms [quick sort, bubble sort, selection sort, linear search, binary search, breadth first search, depth first search, maximum/minimum, mean, count] work  Understand factors that affect the efficiency of an algorithm

Teaching around algorithms There are lots of good activities that illustrate the point that algorithms need to be precise WARNING: What about these other skills?  Debugging algorithms  Designing algorithms  Executing algorithms  Tracing algorithms  Automating (programming) algorithms

Key resources  Progression Pathways (with computational thinking) – CAS Website  Computational thinking guidance – CAS Website

Algorithmic thinking - examples  Writing instructions that if followed in a given order (sequences) achieve a desired effect;  Writing instructions that use arithmetic and logical operations to achieve a desired effect;  Writing instructions that store, move and manipulate data to achieve a desired effect; (variables and assignment)  Writing instructions that choose between different constituent instructions(selection) to achieve a desired effect;  Writing instructions that repeat groups of constituent instructions (loops/iteration) to achieve a desired effect;  Grouping and naming a collection of instructions that do a well-defined task to make a new instruction (subroutines, procedures, functions, methods);

Algorithmic thinking - examples  Writing instructions that involve subroutines use copies of themselves to achieve a desired effect (recursion);  Using a standard notation to represent each of the above;  Creating algorithms to test a hypothesis;  Creating algorithms that give good, though not always the best, solutions (heuristics);  Creating algorithmic descriptions of real world processes so as to better understand them (computational modelling);  Designing algorithmic solutions that take into account the abilities, limitations and desires of the people who will use them;

Task: Paper Cup Activity Key Lesson Vocabulary: Algorithm -  A series of instructions on how to accomplish a task Coding -  Transforming actions into a symbolic language Debugging -  Finding and fixing issues in code Function -  A piece of code that can be called over and over Parameters -  Extra bits of information that you can pass into a function to customize

Cup robotics

Task: Paper Cup Activity Key Lesson Vocabulary: Algorithm -  A series of instructions on how to accomplish a task Coding -  Transforming actions into a symbolic language Debugging -  Finding and fixing issues in code Function -  A piece of code that can be called over and over Parameters -  Extra bits of information that you can pass into a function to customize

Symbols

Example – with 3 cups in a stack

You should get

Now try..  Select one of the pictures to write instructions for  Write instructions ONLY using the symbols given  Swap with another group and see if your instructions work!  Think: How could you extend this exercise

Feedback on paper cup activity  What does it teach?  Who is it suitable for?  What would you teach next?

Progression Pathways

The guessing game Group 1: write the pseudocode for the algorithm underlying the guessing game Group 2: write a flowchart describing the guessing game algorithm Swap and comment Which of the progression pathways skills are within this algorithm

Process Decision Input/output Start/End Flow Pseudo code Send X to Display (or Output) Input or Read from Display to X Repeat /End Repeat While / End While If/End If Set X to

Algorithms unplugged Dance a bubble sort

Task: developing two tasks IF TIME In pairs: Using the list of activities from the previous slide, and the knowledge needed at GCSE/KS3, develop TWO lesson outlines/tasks showing progression – one for KS3 (any year- but you should state) and one for KS4 (any board – but state if relevant) Each activity should be described on one (max two) ppt slides Upload on to the wiki in the area defined as Progression (algorithms)

Learning objectives  You will start to understand what concepts and terminology are used in the area of algorithmic thinking in KS3 and KS4  You will develop an understanding of how children develop understanding of algorithms, using the progression pathway document, particularly  You will be able to plan lessons which demonstrate some progression in algorithmic thinking