More individual differences in language attainment: How much do adult native speakers of English know about passives and quantifiers?

This paper provides experimental evidence suggesting that there are considerable differences in native language attainment, and that these are at least partially attributable to individual speakers’ experience. Experiment 1 tested high academic attainment (hereafter, HAA) and low academic attainment (LAA) participants’ comprehension using a picture selection task. Test sentences comprised passives and two variants of the universal quantification construction. Active constructions were used as a control condition. HAA participants performed at ceiling in all conditions; LAA participants performed at ceiling only on actives. As predicted by usage-based accounts, the order of difficulty of the four sentence types mirrored their frequency. Experiment 2 tested whether the less-educated participants’ difficulties with these constructions are attributable to insufficient experience. After a screening test, low scoring participants were randomly assigned to two training groups. The passive training group were given a short training session on the passive construction; and the quantifier training group were trained on sentences with quantifiers. A series of post-training tests show that performance on the trained construction improved dramatically, and that the effect was long-lasting

Synthesis of Data Word Transducers

In reactive synthesis, the goal is to automatically generate an implementation from a specification of the reactive and non-terminating input/output behaviours of a system. Specifications are usually modelled as logical formulae or automata over infinite sequences of signals ($\omega$-words), while implementations are represented as transducers. In the classical setting, the set of signals is assumed to be finite. In this paper, we consider data $\omega$-words instead, i.e., words over an infinite alphabet. In this context, we study specifications and implementations respectively given as automata and transducers extended with a finite set of registers. We consider different instances, depending on whether the specification is nondeterministic, universal or deterministic, and depending on whether the number of registers of the implementation is given or not. In the unbounded setting, we show undecidability for both universal and nondeterministic specifications, while decidability is recovered in the deterministic case. In the bounded setting, undecidability still holds for nondeterministic specifications, but can be recovered by disallowing tests over input data. The generic technique we use to show the latter result allows us to reprove some known result, namely decidability of bounded synthesis for universal specifications

Strongly universal string hashing is fast

We present fast strongly universal string hashing families: they can process data at a rate of 0.2 CPU cycle per byte. Maybe surprisingly, we find that these families---though they require a large buffer of random numbers---are often faster than popular hash functions with weaker theoretical guarantees. Moreover, conventional wisdom is that hash functions with fewer multiplications are faster. Yet we find that they may fail to be faster due to operation pipelining. We present experimental results on several processors including low-powered processors. Our tests include hash functions designed for processors with the Carry-Less Multiplication (CLMUL) instruction set. We also prove, using accessible proofs, the strong universality of our families.Comment: Software is available at http://code.google.com/p/variablelengthstringhashing/ and https://github.com/lemire/StronglyUniversalStringHashin

Experimental Methods in IIR: The Tension between Rigour and Ethics in Studies Involving Users with Dyslexia

Designing user studies in the interactive information retrieval (IIR) paradigm on people with impairments may sometimes require different methodological considerations than for other users. Consequently, there may be a tension between what the community regards as being a rigorous methodology against what researchers can do ethically with their users. This paper discusses issues to consider when designing IIR studies involving people with dyslexia, such as sampling, informed consent and data collection. The conclusion is that conducting user studies on participants with dyslexia requires special considerations at all stages of the experimental design. The purpose of this paper is to raise awareness and understanding in the research community about experimental methods involving users with dyslexia, and addresses researchers, as well as editors and reviewers. Several of the issues raised do not only apply to people with dyslexia, but have implications when researching other groups, for instance elderly people and users with learning, cognitive, sensory or motor impairments

Application of Kolmogorov complexity and universal codes to identity testing and nonparametric testing of serial independence for time series

We show that Kolmogorov complexity and such its estimators as universal codes (or data compression methods) can be applied for hypotheses testing in a framework of classical mathematical statistics. The methods for identity testing and nonparametric testing of serial independence for time series are suggested.Comment: submitte