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The Trees 3 Program for Windows

Usable under Wine with Mac OS X and Linux

Trees (© Sean Crist and Tony Kroch) is easy-to-use software for drawing syntactic trees and displaying them on screen and in documents. It implements a form of lexicalized Tree Substitution Grammar, which allows the construction of phrase structure trees in an intuitive way, and it supports applying grammatical movement rules to syntactic trees to create syntactic derivations. Click on the above animation for a demonstration of how the program works. A demo version of the program is downloadable from this site.

The Trees program has several uses for teachers and students of natural language syntax, including:

1. building trees and pasting them into word processing documents or web pages.
2. demonstrating syntactic structures and derivations in a computer-equipped classroom.
3. constructing interactive exercises for use in homework assignments.
4. modeling syntactic analyses to explore their descriptive coverage.

The Trees program works with grammar tool files that specify words, grammatical structures, and processes of syntactic composition in lexicalized (optionally) grammar fragments. These fragments can be written by program users to suit their purposes and in pedagogical applications are normally written by the teacher for use with an assignment. The demo archive downloadable from this page contains grammar tools and assignments that have been used in introductory and intermediate courses at Penn and elsewhere. Trees 3 is a Microsoft Windows program but it can be run on an Intel Macintosh under OS X, using the open-source program Wine, which is available in a version for OS X called Darwine. Click here for (easy) instructions on installing Trees into the Darwine environment. Colin Phillips, currently on the faculty of the University of Maryland, has used Trees in an introductory course and has written a review of an earlier version of the program, available here, that appeared in number 3.7 of the linguistics newsletter GLOT International (home page: http://www.glotinternational.com). The program is in use at several universities, including: University of Delaware, University of Edinburgh, Georgetown University, Michigan State University, University of North Carolina, Rutgers University, Simon Fraser University, the University of Wisconsin, and the University of York.

Trees supports a wide range of structures and composition processes. There is special support for X-bar phrase structure but non X-bar structures are also permitted. Transformational movement is supported but simple derivations in Categorial Grammar, Generalized Phrase Structure Grammar, and Tree Adjoining Grammar can also be modeled. The program does not currently support the display of attribute-value matrices.

The program was developed under a grant from the University of Pennsylvania School of Arts and Sciences Instructional Computing Development Fund and is freely available to students and staff of the University of Pennsylvania. The program is also freely available to students and staff at universities that have purchased site licenses for the program.

Other users may download here, for evaluation purposes, a demonstration version of a restricted "player" version of Trees3 that will expire after 30 days. The download includes a grammar tool useful in constructing trees for display in word processing documents and a MS Word file of instructions on how to use the program. The download file is a self-extracting zip archive that will install the program automatically on a double-click.

Trees Player will work with any grammar tool written for Trees3 but it does not permit the writing of new grammar tools. A sample of grammar tools that have been written at Penn for syntax courses is available here.

If you want to keep using Trees Player after 30 days or if you want to write new grammar tools, you must purchase the program. The cost for an individual user is:

$25 for the Trees Player
$50 for the full version with grammar tool writing

The full version of the program comes with a built-in programming language TreeTalk, which allows users to write new grammar tools with rules of syntactic composition that they specify. These grammar tools are useful for creating homework exercises or exam problems in syntax courses and for demonstrating how syntactic analyses work. There is an accompanying manual that explains how to build these grammar tools.

The Trees program can be bought in two ways:

Purchase the program with a credit card from Google Checkout.

Purchase the program with a credit card from the Store.

Multiple user site licenses:

Site licenses are available at higher cost for instructors who want to use the program for teaching purposes. These licenses include multiple copies of the full version of the program. For information on how to purchase a multiuser site license, click here.