To ensure that your results are valid, consider the following guidelines when you collect data, perform the analysis, and interpret your results.
- The data should be continuous or ordinal
- If you have categorical data, you should perform a Cross Tabulation and Chi-Square to examine the association between variables.
- The relationship between variables should be linear or monotonic
- If your variables do not have a linear or monotonic relationship, the results from the correlation analysis will not accurately reflect the strength of the relationship. To check for other forms of relationships, create a Scatterplotor use Simple Regression.
- Unusual values can have a strong effect on the results
- Because unusual values can have a strong effect on the results, create a Scatterplotor use Simple Regression to identify these values. You should investigate outliers because they can provide useful information about your data or process.