For grouped data, frequency tables record the frequency (and associated percentage) and cumulative frequency (and associated cumulative percentage) for the values that fall within each group. Individual qualitative data values may be grouped by a classification variable. Individual quantitative data values may be grouped by defining intervals or cutpoints to bin the data into separate groups.
To properly analyze and interpret results of frequency tables, you should be familiar with the following terms and concepts:
If you are not familiar with these terms and concepts, you are advised to consult with a statistician. Failure to understand and properly apply frequency tables may result in drawing erroneous conclusions from your data. Additionally, you may want to consult the following references:
- Brownlee, K. A. 1965. Statistical Theory and Methodology in Science and Engineering. New York: John Wiley & Sons.
- Daniel, Wayne W. 1995. Biostatistics. 6th ed. New York: John Wiley & Sons.
- Sokal, Robert R. and Rohlf, F. James. 1995. Biometry. 3rd. ed. New York: W. H. Freeman and Co.
- Zar, Jerrold H. 1996. Biostatistical Analysis. 3rd ed. Upper Saddle River, NJ: Prentice-Hall.