Existing research is unclear on how to generate lessons learned for defect prediction and effort estimation. Should we seek lessons that are global to multiple projects or just local to particular projects? This paper aims to comparatively evaluate local versus global lessons learned for effort estimation and defect prediction. We applied automated clustering tools to effort and defect datasets from the PROMISE repository. Rule learners generated lessons learned from all the data, from local projects, or just from each cluster. The results indicate that the lessons learned after combining small parts of different data sources (i.e., the clusters) were superior to either generalizations formed over all the data or local lessons formed from particular projects. We conclude that when researchers attempt to draw lessons from some historical data source, they should 1) ignore any existing local divisions into multiple sources, 2) cluster across all available data, then 3) restrict the learning of lessons to the clusters from other sources that are nearest to the test data.

The Big Australian Speech Corpus project incorporates the strategic goals of 30 Chief Investigators from various speech science areas. Speech from 1000 geographically and socially diverse speakers is being recorded using a uniform and automated protocol plus standardized hardware and software to produce a widely applicable and extensible database – AusTalk. Here we describe the project’s major components and organization; share the lessons learnt from difficulties and challenges; and present the results achieved so far.

This paper provides a spectral analysis of two Australian languages Yolngu Matha (YM), Pitjantjatjara (PTJ) and Australian Aboriginal English (AAE) as spoken in two language communities. The aim of this study is to show clear quantitative spectral differences between Australian Aboriginal English and the two Aboriginal languages. Thirteen speakers of Yolngu Matha (YolNu Matha) ten male, three female and three female speakers of Pitjantjatjara were recorded reading or retelling a passage in their first language and also in English. The results show that there is a difference between the spectral averages of the two language groups with the AAE having higher amplitudes at higher frequencies when compared to the two Australian languages. The Australian Aboriginal language examples all show higher amplitudes for frequencies between 750 Hz and 2 kHz for all speakers. Copyright © 2011 ISCA.

Data miners can infer rules showing how to improve either (a) the effort estimates of a project or (b) the defect predictions of a software module. Such studies often exhibit conclusion instability regarding what is the most effective action for different projects or modules. This instability can be explained by data heterogeneity. We show that effort and defect data contain many local regions with markedly different properties to the global space. In other words, what appears to be useful in a global context is often irrelevant for particular local contexts. This result raises questions about the generality of conclusions from empirical SE. At the very least, SE researchers should test if their supposedly general conclusions are valid within subsets of their data. At the very most, empirical SE should become a search for local regions with similar properties (and conclusions should be constrained to just those regions).

Abstract Summary: EchoLOCATION is a database that provides a comprehensive analysis of the subcellular locations of Escherichia coli K-12 proteins. Locations are predicted by integrating data from a range of publicly available algorithms combined with extensive curation of experimental literature. The data can be searched in a variety of ways and can generate lists of subcellular proteomes for analysis. Experimental evidence supports the locations of over 500 envelope proteins (periplasm, inner and outer membrane). From analysis of disagreements between in silico predictions and experimental data, we provide an analysis of protein types where subcellular prediction algorithms are currently not accurate. Availability: http://www.ecoli-york.org/ Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online.

Basilectal varieties of Australian Aboriginal English (AAE), which are heavily influenced by the indigenous substrate, may have a very restricted set of vowels compared to Standard Australian English (SAE). A comparison of the vowels of a small group of acrolectal AAE speakers with those of the standard accent suggests that even in varieties with the same set of phonemes as SAE, speakers are using a somewhat smaller phonetic vowel space. The lower boundaries of the AAE and indigenous language spaces are very similar and, whereas the SAE vowel space represents an expansion in all directions compared with the indigenous space, the AAE space represents an expansion in an ‘upward’ (lower F1) direction only. Within their respective spaces, the relative positions of the monophthongs are quite similar in SAE and AAE. Diphthong trajectories are also similar, except that some have shorter trajectories (more centralised second targets) in AAE. Most of the differences there are can be viewed as more conservative features in the AAE accent.

Phonologically prestopped nasals occur primarily in central and southern Australian languages. Phonetically prestopped nasals on the other hand, occur in a large number of Australian languages and are not isolated to one particular region. Phonetically prestopped nasals have been analysed as a preservation of spectral characteristics at vowel-sonorant boundaries in languages which have a comparatively large number of sonorant contrasts. In this paper we describe acoustic, articulatory and durational characteristics of rarely mentioned phonetically prestopped laterals, in the Australian language Warlpiri. We conclude that like prestopped nasals, prestopped laterals are likely to be the outcome of a coarticulatory avoidance strategy to preserve the left-edge of the sonorant. While not auditorily salient, we report on the frequent distribution and very distinctive phonetic characteristics associated with prestopped laterals. Copyright © 2008 ISCA.