Lucid Builder v4 Lucid Player v4

What does the Lucid Player do?

Lucid Player main interface example matrix (random access) key
Lucid Player main interface example matrix (random access) key
Lucid Player main interface showing an example dichotomous (pathway) key (insects)
Lucid Player main interface showing an example dichotomous (pathway) key (insects)

The Lucid Player provides the end user the interface for interacting with an identification key created in the Lucid Builder. The Lucid Player supports loading both matrix (random access) and dichotomous keys.

The Lucid Player comprises a main window presenting to the user four lists regardless of the type of key loaded:

Top left window

Matrix key:

Features Available – lists all features and their states that may be used to describe the specimen to be identified

Dichotomous key:

Questions (couplets) Available – holds the questions that need to be addressed at each step (branch point) of the key.

Left bottom window

Matrix key:

Features Chosen – displays features that have been chosen.

Dichotomous key:

History – displays a list of questions that have been answered.

Top right window

Matrix & Dichotomous key:

Entities Remaining – lists all entities in the key that still remain as possible identifications of the specimen being investigated, given the features/questions that have been chosen.

Bottom right window

Matrix & Dichotomous key:

Entities Discarded – lists all entities in the key that have been excluded as a result of the chosen features or answered questions.

When a key is first started, Features Chosen/History and Entities Discarded are empty. A user chooses states of features or answers questions by ticking their check-boxes. In response, the Player progressively removes from Entities Remaining those entities that do not match the chosen states/questions.

By choosing more and more features or questions, the list in Entities Remaining will be gradually reduced until, perhaps, a single entity remains – the specimen has been identified.

In addition to the basic lists of features and entities, a well-designed Lucid key also provides help to users through pictures and web pages illustrating and explaining features and their states, pages with extra information on the entities in the key, feature and entity subsets and dependencies to help organise and streamline the lists.

Please see the Lucid Player Help for more information.

Lucid Builder v4

What does the Lucid Builder do?

Lucid Builder interface example (scoring the key)
Lucid Builder interface example (scoring the key)
Lucid Builder spreadsheet scoring example
Lucid Builder spreadsheet scoring example

The Lucid system comprises a Builder and Player for creating and deploying effective and powerful identification and diagnostic keys. Using the Lucid Builder, a user with knowledge concerning a group of entities (plants, animals, diseases, minerals, archaeological artifacts etc) can create interactive, random-access or dichotomous keys that can be deployed over the Internet, Hard Disk, USB or CD.

Users who wish to identify an animal or plant or some other entity for which a Lucid key has been developed can:

For a random access key “describe” their specimen to the key by choosing features listed in the key that match their specimen. The key progressively eliminates entities that do not match the chosen features until only one or a few possible entities remain.

For a dichotomous key choose answers to a series of questions or statements (couplets) that lead to an identification result. Unlike paper versions of dichotomous keys the Lucid player allows the user to easily keep track of their answers and skip questions to overcome the ‘unanswerable’ couplet problems often seen in larger more complex keys.  

Further information and images can be accessed in fact sheets to confirm the identification.

See the topic “What does the Lucid Player do?“, or read the Lucid Player’s Help, for more information on how identifications are performed in the Player, and for other Player features that have been designed to help in the identification process.

The basic elements of a Lucid key are –

  • a list of Entities.
  • a list of Features and states or Couplets (for a dichotomous key) that can be used to describe those Entities.
  • a matrix of score data for the Features associated with each of the Entities for the Features.
  • various attachments (images, web pages etc) for the Entities and Features, to provide extra information to users.

The Lucid Builder provides all the tools necessary to create the Entity and Feature lists, couplets, encode the score data, and attach information files to items.

Lucid Builder v4

Lucid Builder Registration and Activation

Thank you for purchasing Lucid4. You will need to complete the activation process in order to unlock the software from demonstration (trial) mode. The process for doing this is detailed below. 


The activation process will lock your copy of Lucid4 to the specific computer on which you have installed it. Please submit a support ticket if you need to transfer your licence to another computer. Or request the licence transfer via

Step 1 – Installing Lucid4

When you open the Lucid4 Builder, you will be given the option to register the software now or later.

Lucid Builder Registration dialog
Lucid Builder Registration dialog.

If you choose to register later, you can use the Lucid4 Builder in Demonstration Mode only. In this mode certain features of the Builder (e.g. Save, Save As and Export) will be disabled if the key exceeds 50 features and 15 entities.

Lucid Builder Demonstration Mode notification
Lucid Builder Demonstration Mode notification.

Lucid Builder About Demonstration Mode dialog

Lucid Builder About Demonstration Mode dialog.

If you choose to register now, please note that you must be able to connect to the Internet and have a valid email account in order to complete the registration process.

Step 2 – Registering your copy

To register Lucid4, click the Register button. You will be asked to enter your name, and the email address used when purchasing the software, and the serial number you were emailed after purchase.

Lucid Builder Registration Details dialog
Lucid Builder Registration Details dialog.

Step 3 – Getting your activation code from

Once you have entered the required registration details, if there is an internet connection present the Lucid Builder will attempt to automatically activate your licence over the network.

If the activation fails due to licensing or input errors, a message will be displayed describing the error and the Lucid Builder will enter demonstration mode. Otherwise the Builder will report the activation process was successful and open without restrictions.

If the activation fails due to network connection or general errors a dialog will be displayed with the reason the activation attempt failed. If needed, the activation process can be completed manually by using your account and logging into Once logged in use the left hand menu to select the Manual Activation option ( , paste your registration code found in the LucidBuilder4.registration file located in the C:\Users\<your username>\.lucid folder. If you have a valid licence and an available licence seat you will be sent the activation code.

Activation Notes for Network Administrators

To make the activation process more flexible for computers that are centrally administered and have restricted privileges for non-administrators, the default location for storing the activation files is the user”s default home folder, where a “.lucid” folder will be created.

For example:

In the Windows 10 operating system, the activation files will be stored at:
C:\Users\<your username>\.lucid.

If desired, registration and activation files can also be placed into the Lucid installation folder. This will allow more than one user to use Lucid on the same computer. Alternatively, you may copy the “.lucid” folder into other users” home folders.

Lucid Builder v4

Welcome to the Lucid4 Builder

Lucid Builder Version 4 main interface example
Lucid Builder Version 4 main interface example matrix key (weeds)
Lucid Phoenix main interface with example pathway key (insects)

Welcome to the Lucid4 Builder, one member of the Lucid family of products. The Lucid Builder allows the creation of advanced matrix (random access) or dichotomous identification keys.

Written in Java, Lucid4 is a cross-platform implementation, and will run on any Java-enabled operating system (such as Windows, Macintosh, Unix, Linux, Sun Solaris etc).

Read more about what the Lucid Builder can do.

For additional information on Lucid and related programs, please visit the Lucidcentral website at


A Java Runtime Environment (JRE) must be installed before Lucid will install or run. We recommend installing the latest open JRE from: