Making Sense of Data & Anomalous Results

Making Sense of Data & Anomalous Results

When data is generated by an experiment this is called raw data. This obviously needs to be analysed in some way in order for conclusions to be drawn. Frequently an average needs to be calculated so that comparisons can be made. Three useful kinds of average are the mean, mode and median averages.

Median: This is calculated by arranging the relevant figures in numerical order and identifying the middle value. E.g.

2,5,7, 9, 13, 15, 34, 56, 101 Median = 13

(If there is an even number of figures then you will need to work out the midpoint between the two middle values)

Mode: This is the figure that most often occurs in a series of related figures. In the following set, for example, the mode is 18.

2, 19, 7, 3, 6, 18, 45, 23, 24, 18, 34

Mean: This is the kind of average most of us are familiar with. It involves adding up all of the figures and dividing them by the number of values used.

The range: It may also be useful to calculate the range of a set of figures. This is worked out simply by subtracting the lowest figure from the highest.


Anomalous Results

An anomalous result is one which stands out very obviously from the rest of the figures simply because it breaks the pattern all the other figures have fallen into. This anomalous figure may have a large effect on the range or average and could disrupt the overall results. In the event an anomalous figure is thrown up, the researcher will usually look into it a little further and see if he can come up with a rational explanation. He might include this explanation in his findings so that other people can make greater sense of the results.