## Data Evaluation and Comparisons:

So far, this tutorial has focussed on statistical parameters (such as mean and standard deviation) and linear regression as applied to instrument calibration. In this section, we will look at methods for evaluating specific results. For example, you might want to know if the concentration obtained by a particular method agrees with the true concentration in order to establish whether or not the method was biased. Or, you might want to find out if two different methods yielded similar results or if one was more accurate or precise than the other. Such questions can be addressed using various significance tests, some of which have been mentioned elsewhere and are described in more detail in this section.