How to use PICKEY

The process of computer dialogue identification of a specimen with the aid of the PICKEY program comprises a number of steps. At each step the user has to specify a character most convenient for observation (e.g. number of marginal tentacles for medusae) and to select a state of the specified character mostly corresponding to the properties of the examined specimen. For the above purposes provided are the first and second operational screens of the program.

The first screen comprises text frames with the names of characters, a frame with the name of the key and a frame with the number of taxa included in the list. Major part of the screen is occupied by a frame containing illustration to the current character which is shifted by shifting the cursor.

The second operational screen is separated into several equal areas (between two and nine) filled with illustrations of states of selected character. The user carefully analyses the relevant element for specimen identification and chooses the image mostly adequate for the specimen.

The program offers a possibility to check for correct understanding of the illustration from textual description of the selected character placed on a shifting textual frame. The step is completed by selection the taxa possessing the specified state of the character from the list (at the first step the selection is made from the complete list of taxa included into the key).

In case of two or more taxa included, the program proceeds with the next step. At each step the character proposed by the program are in the order of diminution of their diagnostic value, which is calculated for a particular step by a unique algorithm. It is more advisable to make use of the characters presented by computer in the first place, however, the final decision is taken by the user as atrade-off between safety, accessibility and value of the character. The algorithm for identification of diagnostic value of a character is based on original formula (Lobanov, 1974).

The proper choice of characters would complete the identification process by the demonstration of the total black-and-white and, if possible, colored image of organism as well as the textual description of the taxon (third operating screen).

In case of choice of a key of a set of attributes unsolicited by the author the program gives the appropriate message and enables to return on the previous step of identification or start definition from the very beginning. If the key is uncompleted by the author and there is a situation, when for differentiation of close taxa in a key there are no more characters the program signals about it and shows the list of indiscriminable taxa.

You can finish an identification at every step of the process by selection of total images, and not character states ("peephole" mode).