faqs
>What's needed to host or run an Internet key?
>What's the difference between an Internet key and a CD or hard disk based key?
>Is it possible to have keys that use a combination of CD and the Internet?
>Does Lucid have to download all of the key before it can be used?
See also:
Lucid2 FAQ's
Lucid3 FAQ's
Phoenix FAQ's
Frequently Asked Questions (General)
To view the answers to the most popular questions click on the links featured on the left. If you cannot find the information you are looking for within the FAQs please try the search facility at the top of the page.
Q. What is a key?
A. A key is a tool that, figuratively speaking, unlocks the door to identification of an unknown object or organism. Keys can be built to identify any group of things: the pieces of apparatus in a laboratory, the parts of a car, the species of termites in Africa, the types of stars in our galaxy. Typically, an expert in the relevant field puts together the information and builds the key. Keys are useful in any biological field where large numbers of taxa are difficult to distinguish just by using the naked eye and memory.
The builder of a key must choose characters that best distinguish between taxa to be included. Each character has a number of character states e.g. pink, yellow, blue - for the character "colour of petals". Clearly defining the character states is crucial to the efficient working of a key. Subjective decision making on the part of the user should be avoided e.g. character states "dark pink" and "red" could be interpreted differently by different users.
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Q. What is a dichotomous key?
A. Dichotomous keys are the most common keys encountered. They may be laid out in various ways, but usually form a series of numbered questions arranged in "couplets" as shown below
1. Bark on trunk smooth.................................. 2
Bark on trunk rough.................................... 3
2. Bark mostly white....................................... 4
Bark other colours....................................... 7
Each time a question is answered, the user is directed to the number of a new question-couplet and the key continues to do this until instead of a number, the name of the species (or other taxon) is given. This type of key is called a "dichotomous" key because the meaning of the word is "two branching". The structure of the key is such that each question is actually like a tree branch that has two smaller branches proceeding from it as demonstrated on the next page.
Despite their wide use, dichotomous keys suffer from one very bad problem – you have no choice about the order in which characters are presented. For instance, suppose you are trying to identify a plant and the next couplet is about the colour of the flowers, but the material you have only has fruits. You can go no further with any confidence. Lucid Phoenix can help overcome this problem by allowing you to skip couple questions and help manage your selected path through the key.
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Q. What is a multi-access key?
A. Multi-access Keys, such as those built using Lucid Matrix, do not suffer from the unanswerable couplet problem encountered in a traditional dichotomous key (Lucid Phoenix helps to over come this problem) because multi-access keys allow you to start at any point you choose and to proceed in any order you choose. Computers are ideal to handle these keys. In its database, the key contains all the information about the taxa that are to be identified. The user chooses a character state of a selected character in the key and the multi-access key retains taxa that have the character state; taxa that have a different character state for the selected character are discarded. Next another character is chosen, and again the same process is repeated with the remaining taxa. You can avoid characters that are difficult for you or not appropriate for your specimen.
Q. What is an Internet key?
An Internet key is a Lucid key hosted on a web server. This allows you to make your key available to a wide audience.
Q. What's needed to host or run an Internet key?
For the key's author all that's needed for hosting a Lucid key is a web server and a network connection. The keys can be hosted on any kind of web server such as Microsoft IIS or Apache web server etc. For the potential user of the key they just need to have a Lucid Player installed.
Q. What's the difference between an Internet key and a CD or hark disk based key?
The major difference between a local key (CD or hard disk based key) is where the media is stored. All of the media for CD based keys is located on the CD while an Internet key has the media stored on a web server.
Q. Is is possible to have keys that use a combination of CD and the Internet?
Yes, for example if you were constructing a key which used subkeys, you may wish to publish the main key on CD-ROM as a product while the subkeys could be Internet keys.
Q. Does Lucid have to download all of the key before it can be used?
No. The actual key file the Lucid Player needs to run is usually very small, around 20-40KB. Also the Lucid Player doesn't have to download all of the associated media in one go before the key can be used. It downloads media on an as needed basis and caches it like a web browser, saving the time of downloading the same media multiple times. See Optimising Lucid keys for the Internet.