ISCL Proseminar (Sommersemester 2015)

Grammar Formalisms in Computational Linguistics

Abstract:

Given that natural languages cannot be characterized by simply listing all possible sentences and their meaning, a range of grammar formalisms have been developed to characterize form and meaning in a general and compact way. The approaches differ in terms of their focus, empirical coverage, formal foundations, expressive power, conceptualization of generalizations, and the processing regimes that have been developed for those formalisms.

After a general overview of grammar types in the Chomsky Hierarchy, we will discuss plain context-free grammars as a baseline on which we will introduce and compare several current grammar formalisms. The plan is to include a discussion of Head-Driven Phrase Structure Grammar (HPSG), Tree Adjoining Grammars (TAG), Lexical Functional Grammar (LFG), and Combinatoric Categorial Grammars (CCG).

The focus will be on obtaining a sound working knowledge of how different formalisms capture some of the fundamental phenomena of natural language syntax: argument and adjunct realization, agreement and government, middle-distance phenomena (e.g., equi, raising), long-distance phenomena (e.g., fronting).

While the more recent Chomskyan frameworks (Minimalism, Bare Phrase Structure) are not covered in the course given their lack of relevance for computational (or empirical) linguistic work, the grammar formalisms course essentially addresses a desideratum clearly expressed in Chomsky (1981, pp. 335-6): “It is an open question whether full-scale formalization is a worthwhile endeavor at the moment ... My personal feeling is that the point has been reached where these further steps should be undertaken, that there is sufficient depth and complexity of argument so that formalization will not merely be a pointless technical exercise but may bring to light errors or gaps and hidden assumptions, and may yield new theoretical insights and suggest new empirical problems for investigation.”

Instructor: Detmar Meurers

Tutor: Zarah Weiß

Course meets:

Note: Attendance for lecture and lab sessions is obligatory.

Credits for ISCL BA: 6 SWS = 9 Credit Points
For other degree programs, contact us for requirements and credits.

Moodle: We will be using the university Moodle site for the course, primarily for the discussing forum and to access course materials. Our course is accessible under Moodle at https://moodle02.zdv.uni-tuebingen.de/course/view.php?id=1151.

To log into this specific Moodle site, you use your general ZDV university account id and password. The first time you access the course Moodle site, you need a course subscription password, which you get in class. Moodle and privacy: Note that Moodle generally keeps detailed logs of your interaction with the system, e.g., when you log in, etc.

Email: In the Moodle system everyone in the course can send messages to other participants in the class, and I will use this to contact you for class related matters. Such email gets sent to your regular ZDV account (@student.uni-tuebingen.de). So register in the Moodle during the first week of the semester, and read your university email regularly.

Nature of course and my expectations: This is a core course in ISCL and I expect each participant to take an active role in the class: i) regularly participate in the discussions, ii) read any reading assignments before class, iii) actively participate in the practical sessions and carefully complete all assignments and implementation activities and homeworks.

Grading: The course will be graded based on participation, activities/homeworks (50% of grade), and the final exam (50% of grade), to be held in our last course session (July 23).

Academic conduct and misconduct: Learning and research are driven by discussion and free exchange of ideas, motivations, and perspectives. So you are encouraged to work in groups, discuss, and exchange ideas. At the same time, the foundation of the free exchange of ideas is that everyone is open about where they obtained which information. Concretely, this means you are expected to always make explicit when you’ve worked on something as a team – and keep in mind that being part of a team means sharing the work! For text you write, you always have to provide explicit references for any ideas or passages you reuse from somewhere else. This includes text “found” on the web, where you should cite the url of the web site in case no more official publication is available. Failure to follow these important guidelines is academic misconduct, which will be sanctioned by failing you on the assignment, exam, or the entire class depending on the severity of the violation.

Class etiquette: Please come to class on time, do not pack up early, read or work on materials for other classes during our class. When in the computer lab, only use the computers when you are asked to do a specific activity; do not read email or browse the web. Laptops and all portable electronic devices such as should be switched off for the entire length of the flight, oops, class. If for some reason, you have to leave early or miss class for an important reason, please let me know before class. Note: Following the standard rules, missing more than two meetings unexcused, automatically results in failing the class.

Topics we plan to cover