Introduction

Recap the work done in the last few weeks. Over the last few weeks we have searched for and collected information from websites. We have also created different types of graphs using some of the information we have found.

Today we are going to look at sorting information.

 

 

Storing and sorting information

Information can be stored in lots of different ways, sometimes on paper sometimes digitally on computers and storage drives. We often need to search that information to find something and that can be a lot easier if the information is in some kind of order. Can you think of some examples of when you might search for some information away from a computer? Can you also think of some examples of where people put information in an order? Examples might be things like indexes, contents, dictionaries, phone books, libraries and book shops, clothes sizes in shops, TV guides and on-demand services (like Netflix) might be alphabetical or by genre.

Often these are done by putting things into a numerical or alphabetical order, but sometimes we might want to identify something unknown from within a group, perhaps what species a bird is or what type of mini-beast you’ve found under a log. Asking questions and dividing the possible answers can help us search and sort things to give us answers.

 

Guess Who?

Let’s look at some examples. We’re going to play 'Guess Who', I’m going to pick one of you in my head (write it down on something) but I’m going to keep it a secret, you have to work out who I’m thinking of by asking questions, but I can only answer Yes or No to your questions. The fewer questions the better!

Play the game, recording the number of questions that they ask on their way to the answer. and then consider, did you ask the best questions? What is a useful question?  Establish that questions that roughly split the group in half are the best as they get rid of the most wrong answers and let you find your target faster. So a good first question for that group of data is always ‘Are they a boy?’ or ‘Are they a girl?’

Repeat the game but this time don’t choose one of the class, pick an alien from the slide in the lesson slides. Does this affect the questions that you might ask? How?

 

 

How computers sort things

Explain that computers also sort information all the time, they have different ways of doing it depending on what is, but often it’s done by comparing pairs of data (pieces of information). This activity (from Computer Science Unplugged) shows how a computer might use a sorting network algorithm to order numbers. Do it on the board with (perhaps with post-it notes) and ask the class to help with the sorting.

Pick six random numbers appropriate for your class and write each one on a sticky note. Start with your numbers in a random order on the left in the IN section, each number in its own box. Follow the arrows, when two numbers reach a circle, you compare them. The biggest number goes UP (follows the upper arrow) the smallest number goes DOWN (follows the lower arrow). Do this for all numbers and follow all the arrows. Are your numbers in the correct order at the end?

 

 

A branching database is very similar to the examples we’ve already looked at. Demonstrate a simple example using 2Question from Purple Mash. You can find this in Tools > Maths and Data Handling. 

 

 

When 2Question loads, start by thinking of four mini-beasts or animals that we have talked about in the last few lessons. In this example we’ll use a spider, a bee, a worm and a ladybird.

Click the 'Click to edit' button under the prompt.

 

 

This opens the card editor and lets you begin your branching database. Ask the class Can you think of a yes/no question that could separate our creatures into two halves? Why is ‘is it yellow?’ a bad questions? Use one of their examples or something like ‘can it fly?’

Add the question to the Question Text box and then add Yes and No to the choice button boxes. You can also add a quick picture if you wish that illustrates the question. Click OK when done.

 

 

Two new prompt boxes will appear on either side of the branching diagram, with a Yes and a No branch.

 

 

Consider how this question will split your four creatures. In this example, a bee and a ladybird would follow the 'yes' side, a spider and a worm would follow the 'no' side. For each side of the diagram add another question that divides the creatures that are left, for example, Can it sting you? Does it have legs? 

 

 

Again, add the Yes and No answer buttons and a picture. Ask the class Does this now sort all our creatures? Where does each one go? Add them into the final set of four prompt boxes. These are just for our answers, so as you edit each one, the Question text should now just be the name of the creature, the picture should be the creature and also tick the 'This is a final answer card' box so it removes the answer buttons. 

 

 

Your finished branching database should look a bit like this.

 

 

Test the tree with the Play button at the top of the screen. Ask someone in the class to think of one of the four creatures, but to keep it secret.

The database will go through the questions, and, as long as they answer honestly, it will lead you to their creature choice.

 

 

Ask the students to think of four animals or mini-beasts of their own and have a go at creating their own branching database. Remind them about only asking yes/no questions. Test each others’ databases at the end. More able students or pairs of children might be able to have a go at a larger database to sort eight creatures.

 

Other useful resources

You find some other nice resources for classifying and sorting activities here:

• BBC Bitesize paper activity
• Crickweb activities (see Variation and Minibeast classification)