For the graph to represent your data most effectively, consider the following guidelines.
The sample size should be less than approximately 50
An individual value plot works best when the sample size is less than approximately 50. If the sample is too large, the data points on the plot may be too densely packed together and the distribution may be difficult to assess. If the sample size is greater than 50, consider using a boxplot or a histogram instead.
The sample data should be selected randomly
In statistics, random samples are used to make generalizations, or inferences, about a population. If your data were not collected randomly, your results may not represent the population.