Study design and preparation

The definition of the research question will also direct the choice of the most suitable experimental design and, consequently, will shape the data analysis plan, which is a critical part of metabolomics. A common type of research question consists of comparing groups of samples, where a group can be defined as a set of biological samples with an important characteristic in common. The last point is particularly critical, and it is also one of the weaknesses of many large-scale metabolomics research projects for biomarker discovery. Estimating, a priori, how many samples should be analyzed to arrive at a particular level of certainty is often difficult if impossible. Experimental Design is the field in statistics aiming to maximize the efficiency of experiments: as much information as possible is obtained with the least effort. The peak list will be then the output of a specific software and to exactly reproduce it, it would be mandatory to use the very same software