5. What are the "key" modeling points?

5.1 The meaning of the model

When estimating parameters, it is imperative to choose as x-values those known with the least uncertainty (these are not always the standard values). When daughter solutions are produced by diluting a mother solution, it is not uncommon for the uncertainties associated with the dilutions (and highly correlated with each other) to be greater than the uncertainties in the reading (in the case of optical densities, for example). In this way, the model is sometimes directly in the right direction (from y to x ), sometimes in the wrong direction (from x to y ). In the latter case, the estimated model...