Frequency tables and Diagrams

Graphs and charts

Please refer to your Molly Marshall textbook for advice on graphs and charts. You need to know how to construct and interpret the following types of graph/chart. When you construct graphs and charts you will get marks for an informative title where both variables (IV and DV or co-variables are mentioned). You will get a mark for labeling both axes appropriate including the units as necessary.

Bar charts

On a bar chart, you are usually drawing bars to represent average scores per group or conditions and the bars should not touch the y axis or each other.

Histograms

If you are drawing a histogram this is to show the spread of the data and it will show many people (frequency – y axis) attained a certain score for example on the x axis, e.g. scores on a memory test: 0-5, 5-10, 11-15, 16-20 etc. On a histogram the bars should touch each other as the data on the x axis is continuous data. Histograms are sometimes used to see whether the data appears normally distributed or whether it has a positive or negative skew.

Scattergrams

Scattergrams are used to present data from correlational studies, where you plot the scores one against the other. They will have a series of scatted points or little crosses demonstrating each pair o scores on the graph and you will need to look at the pattern or trend in the scores, are they demonstrating an apparent positive correlation, negative correlation or no correlation.