## Thursday, 9 June 2016

### Constructing a Graph

Yesterday, we looked at how to construct a graph. There were a couple of key points:

1. Put the independent variable (the thing we changed on purpose) on the x-axis.
2. Put the dependent variable (the other thing that we measured) on the y-axis.
3. Use the aim of the investigation to write a good title.

Now, we are ready to start...

The next part was the hardest bit. We looked for the largest value for the independent variable and added up how many lines/boxes there were across the x-axis. This helped us work out the scale (the difference between each number we write along the axis). A scale is very important for a graph. Without the numbers going up in regular amounts (in 10's in the example above), the graph is meaningless.

We then did the same thing for the y-axis. In this example, a difference of 4 was decided to be the best for the data we had. Note that this is a different scale to the x-axis. That is okay, so long as it is still a scale.

Once we had done all of that, we started to plot our data...

For our rugby investigation, we have found the data very difficult to interpret, because we could not control the angle well enough. There are some good little trends that we will look at in today's lesson. There is also some good Science behind the trends we can see on the graph.