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Multi-access Key
In biology or medicine, a multi-access key is an identification key which overcomes the problem of the more traditional single-access key In phylogenetics, a single-access key (also called dichotomous key, sequential key, analytical key, or pathway key) is an identification key where the sequence and structure of identification steps is fixed by the author of the key. At each point i ...s (dichotomous or polytomous identification keys) of requiring a fixed sequence of identification steps. A multi-access key enables the user to freely choose the characteristics that are convenient to evaluate for the item to be identified.Pankhurst, R. J. 1991. Practical Taxonomic Computing.Winston, J. 1999. Describing Species. Columbia University Press. Although good single-access keys will try to start with characters that are reliable, convenient to observe and generally available throughout most of the year, it is often impossible to achieve this for all taxa in a key. A multi-access key lets ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identification Key
In biology, an identification key, taxonomic key, or biological key is a printed or computer-aided device that aids the identification of biological entities, such as plants, animals, fossils, microorganisms, and pollen grains. Identification keys are also used in many other scientific and technical fields to identify various kinds of entities, such as diseases, soil types, minerals, or archaeological and anthropological artifacts. Traditionally identification keys have most commonly taken the form of single-access keys. These work by offering a fixed sequence of ''identification steps'', each with multiple alternatives, the choice of which determines the next step. If each step has only two alternatives, the key is said to be dichotomous, else it is polytomous. Modern multi-access or ''interactive keys'' allow the user to freely choose the identification steps and their order. At each step, the user must answer a question about one or more features (''characters'') of the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-access Key
In phylogenetics, a single-access key (also called dichotomous key, sequential key, analytical key, or pathway key) is an identification key where the sequence and structure of identification steps is fixed by the author of the key. At each point in the decision process, multiple alternatives are offered, each leading to a result or a further choice. The alternatives are commonly called "leads", and the set of leads at a given point a "couplet". Single access keys are closely related to decision trees or self-balancing binary search trees. However, to improve the usability and reliability of keys, many single-access keys incorporate reticulation, changing the tree structure into a directed acyclic graph. Single-access keys have been in use for several hundred years. They may be printed in various styles (e. g., linked, nested, indented, graphically branching) or used as interactive, computer-aided keys. In the latter case, either a longer part of the key may be displayed (opt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |