There are three built-in and configurable end user GUIs. Although NXT comes with a generic display and a generic search utility so that it can do at least something with corpora in the correct format "out of the box", these GUIs are different in kind - they are intended for actual work. They're really just configurable annotation tools for common interface requirements.

Continuous Signal Labeller

The first is for creating timestamped labels against signal, with the labels chosen from an enumerated list. This can be used for a very wide range of low-level annotations, such as gaze direction, movement in the room, rough starts and ends of turns, and areas to be included in or excluded from some other analysis. The tool treats the labels as mutually exclusive and exhaustive states; as the user plays the signal, whenever a new label is chosen (either with the mouse or using keyboard shortcuts), that time is used both for the beginning of the new label and the end of the old one. Although there are several similar tools available, this tool will work on either audio or video signals, including playing a set of synchronized signals together, and works natively on NXT format data, which is of benefit for user groups that intend to use NXT for further annotation. It does not, however, currently include either the palette-based displays popular from Anvil and TASX, or waveform display, and therefore is unsuitable for many kinds of speech annotation. We've already had a request to augment the tool (currently being beta-tested) to allow free text entry associated with a tag, where the signal would pause automatically when the code starts, wait for type-in, and then continue playing. We are considering this. We are also considering an additional coding interface that allows the user to choose start and end times by mouse down/mouse up on a time slider before choosing a label.

Discourse entity and relationship coder

The second end user GUI is for coding discourse entities above an existing text or speech transcription. Coding is performed by sweeping out the words in the named entity and then mousing on the correct entity type from a static display of the named entity type ontology, or by keyboard shortcut. It can be used for any coding that requires the user to categorize contiguous stretches of text (or of speech by one person) using labels chosen from a tree-shaped ontology. In addition, it allows the user to indicate directional relationships between two coded entities, with the relationship categorized from a set of labels. The most common uses for this style of interface are in marking up named entities and coreferential relationships.

Discourse segmenter

The final GUI is for segmenting discourse into contiguous stretches of text (or of speech by one person) and categorizing the segments. The most common use for this style of interface is a dialogue act coder. Coding is performed by marking the end of each discourse segment; the segment is assume to start at the end of the last segment (or the last segment by the same speaker, with the option of not allowing segments to draw words across some higher level boundary, such as previously marked speaker turns). A permanent dialogue box displays information about the currently selected act and allows a number of properties to be specified for it beyond simple type. The coding mechanisms supported include a tickbox to cover boolean properties such as termination of the act before completion, free text comments, and choice from a small, enumerated, mutuallly exclusive list, such as might be used for noting the dialogue act's addressee. Although this structure covers some styles of dialogue act coding, this tool is not suitable for schemes such as MRDA where dual-coding from the same act type list is allowed. This tool additionally allows the user to indicate directional relationships between acts using the same mechanism as in the discourse entity coder, although for current dialogue act schemes this is a minority requirement.

Tool configuration

See How to configure built-in NXT tools.


Last modified 04/13/06