#CaughtInTheNet – Year 7 Computing

This is a brief outline of Year 7’s first three Computing lessons this year.

In the first lesson we talked briefly about computer networks and they wrote a definition of a computer network for their dICTionary. We then left the ICT room and went out onto the tennis courts. The children took their chairs with them and I asked them to sit themselves in a line. I explained that they were now nodes on the network and the child on the end was the hub. I then “connected” the “network” with some string to form a bus network and passed a tennis ball down the line to represent the data. We talked about how if the connection broke then communication with the end nodes on the network would not be possible.

The children then rearranged themselves into a ring network and were reconnected. This time they realised that they could pass the ball in either direction so that if there was one break in the connection then every node was still contactable.

Next we formed a star network and finally a mesh network where every node was connected to every other node. This took up a lot of string.

Back in the ICT room the children wrote a list  – networks = [“bus”, “ring”, “star”, “mesh”]

They then investigated just how many connections would be needed for a full mesh network with nodes.

Lesson 2 – Protocols and Packets

I explained that a protocol is a defined set of rules that need to be followed and as a class we came up with a Letter Writing Protocol (LWP). The children then wrote their version of a Letter Sending Protocol (LSP).

We then discussed why data is split into packets to be transmitted. The children were given a blank 3×3 grid and were asked to draw a treasure map on the grid. They then had to follow a protocol:

• write the coordinates in the top-left corner of each square (A1, B1, C1, A2 etc)
• Write the name of the intended recipient on the reverse (the address)

They then cut up their grid into 9 smaller squares and placed them all in one plastic tub. The squares were all shuffled about as the children formed themselves into a “ring network”. Each child was handed nine random squares from the tub and the challenge was to see if we could get everyone to receive their intended message. On the command “Pass” each child passed one square to their right and received from their left. If they received a square with their name on they kept it in front of them and as the activity progressed they were able to recreate the map that had been sent to them.

The children were then asked to write their Treasure Map Transfer Protocol.

Lesson Three – “The Birth of the Internet”

In this lesson I will ask the children to start off by simply drawing the Internet in their books. I will also then ask them questions such as “When was the Internet invented?” just to see what they think. I want them to then think about the origins of the Internet and why it was created.

I have recently found the following description about the birth of the Internet (well Arpanet) written by sci-fi author, Bruce Sterling http://www.internetsociety.org/internet/what-internet/history-internet/short-history-internet and, using Plotbot, have adapted it into a short script for the children to record as a radio play. Hopefully I will be able to post the results next week.

Here is the script.