20,033 research outputs found
Syn-QG: Syntactic and Shallow Semantic Rules for Question Generation
Question Generation (QG) is fundamentally a simple syntactic transformation;
however, many aspects of semantics influence what questions are good to form.
We implement this observation by developing Syn-QG, a set of transparent
syntactic rules leveraging universal dependencies, shallow semantic parsing,
lexical resources, and custom rules which transform declarative sentences into
question-answer pairs. We utilize PropBank argument descriptions and VerbNet
state predicates to incorporate shallow semantic content, which helps generate
questions of a descriptive nature and produce inferential and semantically
richer questions than existing systems. In order to improve syntactic fluency
and eliminate grammatically incorrect questions, we employ back-translation
over the output of these syntactic rules. A set of crowd-sourced evaluations
shows that our system can generate a larger number of highly grammatical and
relevant questions than previous QG systems and that back-translation
drastically improves grammaticality at a slight cost of generating irrelevant
questions.Comment: Some of the results in the paper were incorrec
Automated Crowdturfing Attacks and Defenses in Online Review Systems
Malicious crowdsourcing forums are gaining traction as sources of spreading
misinformation online, but are limited by the costs of hiring and managing
human workers. In this paper, we identify a new class of attacks that leverage
deep learning language models (Recurrent Neural Networks or RNNs) to automate
the generation of fake online reviews for products and services. Not only are
these attacks cheap and therefore more scalable, but they can control rate of
content output to eliminate the signature burstiness that makes crowdsourced
campaigns easy to detect.
Using Yelp reviews as an example platform, we show how a two phased review
generation and customization attack can produce reviews that are
indistinguishable by state-of-the-art statistical detectors. We conduct a
survey-based user study to show these reviews not only evade human detection,
but also score high on "usefulness" metrics by users. Finally, we develop novel
automated defenses against these attacks, by leveraging the lossy
transformation introduced by the RNN training and generation cycle. We consider
countermeasures against our mechanisms, show that they produce unattractive
cost-benefit tradeoffs for attackers, and that they can be further curtailed by
simple constraints imposed by online service providers
- …