One of the quantifiers that we use in this contribution describes a measure of order for a sample: the Normalized Shannon Entropy also known as Shannon Evenness Index [803] . This section focuses on this quantifiers use and importance (refer to the 'Materials and Methods' section to see how this measure is calculated). In Sample 4 all probes have the same expression therefore it has the highest achievable value of Normalized Shannon Entropy (H = 1). The Normalized Shannon Entropy values for samples 1 and 2 are the same (H = 0.82). Sample 3, which tends to be less peaked and has the two most significantly expressed genes with the same value, has a higher value of Normalized Shannon Entropy (H = 0.92) (see Figure 21 ).