Early cases labeled them "the juvenile, possessed or insane".
Unlike the interactions from the DIP, those interactions are inherently directed since one protein is always labeled as bait and other as prey (in many cases this labeling is unrelated to the actual experimental roles of the proteins).
However, unlike their scheme, trees that have labels on branches or nodes other than characters or to define branching events were included, since in many cases these labels refer to classification categories that also reflect shared characteristics (e.g., amniotes).
DON'T BE OBVIOUS -- Many people carry their laptops in a carrying case labeled "Dell," "I.B.M".
Third, population labels (ethnicity, language and geographic 'origin') are often used and understood to be rigid entities, but it is widely recognized that in many cases these group labels are very flexible and influenced by social factors and distance.
These challenges primarily relate to the 'multi-class' nature of the problem, as ontologies have often very large numbers of classes, the 'structured dependency relations' between these classes (i.e. the axioms in the ontology) and, in many cases, the 'multi-label' nature of the classification problem as data items are usually annotated to more than one ontology class.
Furthermore, the inclusion of extinct taxa is significantly correlated with variation in branch length (Fisher's test, df 1, p < 0.001), suggesting that differing branch length is being used as a diagrammatic representation of an absolute or relative time dimension; however, in many cases, extinct taxa are not labeled as such.
Treating missing labels as negative labels is one of the approaches to handle missing labels in MLC problems [45], as well as because negative labels in many cases reflect the majority of all target labels for the examined HTS assays that happen to be inactive in the assay.
In many cases, it is important to label cells that express an untagged transgene.
