Extracting knowledge from unstructured text is a long-standing goal of NLP. Al- though learning approaches to many of its subtasks have been developed (e.g., pars- ing, taxonomy induction, information ex- traction), all end-to-end solutions to date require heavy supervision and/or manual engineering, limiting their scope and scal- ability. We present OntoUSP, a system that induces and populates a probabilistic on- tology using only dependency-parsed text as input. OntoUSP builds on the USP unsupervised semantic parser by jointly forming ISA and IS-PART hierarchies of lambda-form clusters. The ISA hierar- chy allows more general knowledge to be learned, and the use of smoothing for parameter estimation. We evaluate On- toUSP by using it to extract a knowledge base from biomedical abstracts and an- swer questions. OntoUSP improves on the recall of USP by 47% and greatly outperforms previous state-of-the-art ap- proaches.

(****) Sentence to logical form mapping using CCG and unification (UBL) instead of GenLex. Geo dataset, four languages, two meaning representations (funql, lambda). Start with single lex item for each sentence mapping it to LF. Introduce vertical bar | to ccg which can match / or \. (ZC07 similar?) Understand the SGD gradient possibly reading CC07. Starting with single lex item and trying splits look much less ad-hoc than ZC05,07 with Genlex and initial lexicon. Only the proper noun NPs (e.g. Texas) are in the initial lexicon. 4.1 splitting constraints interesting, can learn them from data? The split-merge process seem a bit ad-hoc, a more principled Bayesian approach may be possible. Good related work discussion in Sec 6. UBL geo880: p=.941 r=.850 f=.893 UBL-s (2pass): p=.885 r=.879 f=.882

We present a system that learns to fol- low navigational natural language direc- tions. Where traditional models learn from linguistic annotation or word distri- butions, our approach is grounded in the world, learning by apprenticeship from routes through a map paired with English descriptions. Lacking an explicit align- ment between the text and the reference path makes it difficult to determine what portions of the language describe which aspects of the route. We learn this corre- spondence with a reinforcement learning algorithm, using the deviation of the route we follow from the intended path as a re- ward signal. We demonstrate that our sys- tem successfully grounds the meaning of spatial terms like above and south into ge- ometric properties of paths.

Current approaches to semantic parsing, the task of converting text to a formal meaning representation, rely on annotated training data mapping sentences to logi- cal forms. Providing this supervision is a major bottleneck in scaling semantic parsers. This paper presents a new learn- ing paradigm aimed at alleviating the su- pervision burden. We develop two novel learning algorithms capable of predicting complex structures which only rely on a binary feedback signal based on the con- text of an external world. In addition we reformulate the semantic parsing problem to reduce the dependency of the model on syntactic patterns, thus allowing our parser to scale better using less supervision. Our results surprisingly show that without us- ing any annotated meaning representations learning with a weak feedback signal is ca- pable of producing a parser that is compet- itive with fully supervised parsers.

We present a novel framework for learning to interpret and generate language using only per- ceptual context as supervision. We demonstrate its capabilities by developing a system that learns to sportscast simulated robot soccer games in both English and Korean without any language-specific prior knowledge. Training employs only ambiguous supervision consisting of a stream of descrip- tive textual comments and a sequence of events extracted from the simulation trace. The system simultaneously establishes correspondences between individual comments and the events that they describe while building a translation model that supports both parsing and generation. We also present a novel algorithm for learning which events are worth describing. Human evaluations of the generated commentaries indicate they are of reasonable quality and in some cases even on par with those produced by humans for our limited domain.