Presenting results using tables and graphs

In a nutshell

During an experiment, data is collected in the form of a table. This information is the 'raw' data and often needs to be presented in a more simple form. This often is through the use of graphs.

Tables

Recording data in a table allows you to record all the necessary information in an organised way. Before starting an experiment it is helpful to think about headers for variables you expect to collect and any other additional information is recorded. The column headings should also include units. The table should include the data from all repeats of the experiment.

Graphs

There are many types of graphs which can be used to show data in different ways. Graphs are a useful way of being able to see trends and overall results. The type of graph chosen depends on the data set.

Choosing a graph

There are two types of graphs which are commonly used.

Type of graph	description	example
Scatter graph	Scatter graphs are useful for continuous data. Continuous data is data which can have an infinite value.	The time taken for a solution to boil.
Bar graph	Bar graphs are useful for showing categoric data sets. Categoric data falls into distinct categories or groups.	The colour produced in a Fehling's test tube.

The graphs should contain axes which include units. It is important to also use a sharp pencil to achieve clear data points. When drawing a graph it is also important to choose a sensible scale.

Example

If you have a dataset from an experiment where the amount of water produced ranges from $0.9 \ ml - \ 45 \ ml$ , it would be appropriate for the axis to be $0 \ - 50 \ ml$ rather than $0 \ - 100 \ ml$ .

Significant figures

The first significant figure of a number is the first number which isn't zero and the second is the following digit and so on. When conducting an experiment it is important to write down the number of significant figures you have rounded to. When changing between different units it is important to round to the same number of significant figures.

Example

If the results from an experiment is $0.058 \ seconds$ and you are reporting data to one significant figure, the time will be recorded as $0.06 \ seconds$ .

In exam questions, it's important to round to the lowest number of significant figures given in the question.