A histogram is a bar graph of a frequency distribution.

Using a Histogram it can be evaluated visually whether the data are distributed symmetrical, Normal or Gaussian (see Normal distribution) or whether the distribution is asymmetrical or skewed.

When the distribution is not Normal, it cannot accurately be described by mean and standard deviation, but instead the median, quartiles and percentiles should be used. The latter statistics are reported in the Summary statistics results.

Required input

  • Select the variable of interest.

  • Optionally select a filter to include a subset of cases.


  • Show Normal distribution: option to have a Normal distribution curve (with Mean and Standard Deviation of the data represented in the histogram) superimposed over the histogram.
  • Relative frequency: option to express frequencies as percentages.

See also


Go to Histogram.