Before results may be displayed, test answers must be collected either using the Tester program or by manual entry of answers in the Manual Entry screen. The Recalculate Button must be pressed to mark the answers and perform statistical calculations. The View Histogram option is only applicable to tests of “Exam”, “Survey” and “Election” type. Statistics are only reported for the “Exam” type.
If results have not been calculated a message will appear advising that results must be defined and access to the View Histogram screen will be blocked.
Clicking on the field to the right of the Test Name Field displays a list of graph types which may be used to plot the data.
Double click on a list choice to select the plot type.
The appearance of the View Histogram screen is as follows:
For exam test types, plots include Mean and Standard Deviation statistics. Note that tests of “Election” and “Survey” type do not display statistics but rather use the entire screen for display. They are only viewable by question as results do not exist for the entire test in these cases.
Plots display the number (frequency) of candidates obtaining each test score.
Field 
Description 


Mean 
The Mean is a measure of central tendency. The mean is the sum of a set of measurements divided by the number of measurements in the set. 


Standard Deviation 
The standard deviation is the square root of the sum of squares of deviations about the mean. This is a measure of the degree of scatter of the distribution. 

The Recalculate Button marks test answers and calculates statistics for this test. 




The RePlot Button rereads the statistics for this test and replots the graph. 

The Preview Button is used to display how this graph will appear when printed. 
Note that it may be necessary to reduce the size of margins to ensure that the plot will appear on the minimum number of pages.
The Histogram – Vertical plot type is displayed above. Examples of the alternative plot types are as follows: