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|Table of Contents Bivariate Data Correlation Confounded Variables|
|See also: chance correlations|
After having completed the experiments by end of March of the next year, the researcher started to analyse the data. The results clearly indicated different concentrations of the harmful substances for the cold and the warm seasons. However, since the sampling device had to be exchanged in autumn, the researcher did not know whether the difference was due to the different conditions during winter and summer, or due to the replaced sampling device.
In this case there are two factors (or variables) which are said to be confounded with respect to the outcome of the experiment: average daily temperatures, and the effectiveness of the sampling device.
Last Update: 2006-Jšn-17