In one embodiment, one or more processor-readable media can be configured to store code representing instructions that when executed by one or more processors can cause the one or more processors to select a first relationship rule based on a first combination of parameters including a first parameter, and based on a hierarchical position of the first parameter within a hierarchical structure of a set of parameters from a biological category. A first statistical value can be defined based on a plurality of test values and based on the first relationship rule. A second statistical value can be defined based on a second relationship rule and based on a second combination of parameters. The second relationship rule can be selected based on a hierarchical position of the second parameter within the hierarchical structure of the set of parameters.