The tool can be used by researchers who work in the framework of B&B to perform calculations of NAD in a robust way. To compute the preferability of a given cluster, the user simply writes it in the input box. The user does not have to take care about the values of POA or MOA as the tool is distributed with a database of default values for specific phonemes as well as with a set of methods which perform the necessary mathematical operations. The application automatically carries out all the calculations and provides the user with the NAD values along with a visual indication of the preferability of the cluster (green or red). The input can be specified by the user either by writing or copying and pasting the text into the input box or by clicking the IPA symbols located in the table next to the input box. It is possible to calculate the preferability of more than one cluster at a time; this is done by writing one cluster per line.
The tool makes use of standard IPA symbols to identify individual consonants in a cluster. In addition, vowels are identified with the use of the V symbol or a vowel (extended for English and Polish). Providing the V symbol in a cluster is necessary in order to specify the position of (a) vowel(s) relative to the cluster and, consequently, the word position of the cluster. For example, the string stV would be recognized as a word-initial /st/ cluster, while Vst would be treated as a word-final /st/ cluster. The tool also recognizes word-medial clusters, e.g. VstV. Both two- and three-segment clusters are supported in all word positions. The program validates user input so that it returns a user-friendly message when incompatible input is given. The user can define a number of settings when using the tool. A drop-down list located above the IPA symbols provides a list of supported languages. The default language is English. When the user chooses a language, the program displays the possible segments for that language along with the default POA and MOA values for the segments. It is also possible to control the way NAD is calculated by deselecting the checkbox next to the language selection list. By turning this option off, the program will not take into account sonority when computing the preferability of clusters and will estimate NAD on the basis of MOA and POA.