If you are using a Crosstab view or Chart with a field and measure, the system will group the measure into a summary calculation.
Right-click on the measure name in the Rows or Columns area and select Change Summary Calculation.
By default the Summary Calculation will create a Sum calculation. It may make more sense for your analysis to calculate an average or a count of entries.
Further information
For more information on working with Summaries refer to the following articles: