To ensure that your results are valid, consider the following
guidelines when you collect data, perform the analysis, and interpret your
- The data must be continuous, such as the weights of packages
- Continuous data has an infinite number of values between any two
values. For more information on data types, go to
types you can analyze with a hypothesis test.
- The sample data should be selected randomly
- In statistics, random samples are used to make generalizations, or
inferences, about a population. If your data are not collected randomly, your
results may not represent the population. For more information, go to
in samples of data.
- Each observation should be independent from all other observations
- For observations to be independent, the value of a particular
observation does not depend on any previous observation. If your observations
are not independent, your results may not be valid. For more information, go to
are dependent and independent samples different?.
- The sample size should not be small
- If your sample size is small, the resampling results may be
unreliable. To ensure that your results are valid, collect a medium to large
sample. An adequate sample size depends on the characteristics of the data. Use
the histogram to determine whether your sample size is large enough.