Graphing in Science

Outlines the three basic type of graphs in Science: line graphs, column graphs and histograms.

1. LINE & COLUMN GRAPHS LO: Plot data accurately using the appropriate graph type

2. What does this information tell you? Years since new power station opened . Number of fish in local lake. 3 396 7 386 9 382 21 358 30 ?

3. People are much better at reading images and shapes compared to raw numbers.

4. Graphs always tell you two pieces of information. That is why there are two ‘axes’ Vertical axis – the variable that you measure. Dependent variable. ( E.g. mm of rain) Horizontal axis – the variable you change. Independent variable. Line graphs are only used when the data (information) is ‘continuous’

5. In science we don’t actually plot from point to point as the results are rarely ‘perfect’. There are many factors influencing the result collected. We just draw a straight line (a line of best fit). Try to go through as many points as you can. If there are any left over – put the same number of plots either side of your line. Line of best fit

6. Column Graphs A column graph is a graphical display of data using bars of different heights. It is a really good way to show relative sizes – the most frequent occurrence is the tallest column. Column graphs are good to use when your data is in ‘categories’ (such as “Soccer”, “Softball”, etc.)

7. Column Graph vs Histogram When your data is continuous (such as a person’s height) then it is best to use a Histogram As you can see from the example above, because people can have a range of heights, the columns are touching (there’s no gap between them).

8. Graphs MUST... 1. Always have a suitable title 2. Always show the units of measurement 3. Always have the axes labelled. 4. Always be immaculately neat. 4. Always be done in pencil and ruler. That spells T.U.L.I.P.

9. Graph this!