Structure or Noise?

We show how rate-distortion theory provides a mechanism for automated theory building by naturally distinguishing between regularity and randomness. We start from the simple principle that model variables should, as much as possible, render the future and past conditionally independent. From this, we construct an objective function for model making whose extrema embody the trade-off between a model's structural complexity and its predictive power. The solutions correspond to a hierarchy of models that, at each level of complexity, achieve optimal predictive power at minimal cost. In the limit of maximal prediction the resulting optimal model identifies a process's intrinsic organization by extracting the underlying causal states. In this limit, the model's complexity is given by the statistical complexity, which is known to be minimal for achieving maximum prediction. Examples show how theory building can profit from analyzing a process's causal compressibility, which is reflected in the optimal models' rate-distortion curve--the process's characteristic for optimally balancing structure and noise at different levels of representation.Comment: 6 pages, 2 figures; http://cse.ucdavis.edu/~cmg/compmech/pubs/son.htm

The calculative reproduction of social structures : The field of gem mining in Sri Lanka

Peer reviewedPostprin

Stepwise API usage assistance based on N-gram language models

Software development requires the use of external Application Programming Interfaces (APIs) in order to reuse libraries and frameworks. Programmers often struggle with unfamiliar APIs due to their lack of resources or less common design. Such difficulties often lead to an incorrect sequences of API calls that may not produce the desired outcome. Language models have shown the ability to capture regularities in text as well as in code. In this work we explore the use of n-gram language models and their ability to capture regularities in API usage through an intrinsic and extrinsic evaluation of these models on some of the most widely used APIs for the Java programming language. To achieve this, several language models were trained over a source code corpora containing several hundreds of GitHub Java projects that use the desired APIs. In order to fully assess the performance of the language models, we have selected APIs from multiple domains and vocabulary sizes. This work allowed us to conclude that n-gram language models are able to capture the API usage patterns due to their low perplexity values and their high overall coverage, going up to 100% in some cases, which encouraged us to create a code completion tool to help programmers stay in the right path when using unknown APIs while allowing for some exploration.O desenvolvimento de software requer a utilização de Application Programming Interfaces (APIs) externas com o objectivo de reutilizar bibliotecas e frameworks. Muitas vezes, os programadores têm dificuldade em utilizar APIs desconhecidas, devido à falta de recursos ou desenho fora do comum. Essas dificuldades provocam inúmeras vezes sequências incorrectas de chamadas às APIs que poderão não produzir o resultado desejado. Os modelos de língua mostraram-se capazes de capturar regularidades em texto, bem como em código. Neste trabalho é explorada a utilização de modelos de língua de n-gramas e a sua capacidade de capturar regularidades na utilização de APIs, através de uma avaliação intrínseca e extrínseca destes modelos em algumas das APIs mais utilizadas na linguagem de programação Java. Para alcançar este objectivo, vários modelos foram treinados sobre repositórios de código do GitHub, contendo centenas de projectos Java que utilizam estas APIs. Com o objectivo de ter uma avaliação completa do desempenho dos modelos de língua, foram seleccionadas APIs de múltiplos domínios e tamanhos de vocabulário. Este trabalho permite concluir que os modelos de língua de n-gramas são capazes de capturar padrões de utilização de APIs devido aos seus baixos valores de perplexidade e a sua alta cobertura, chegando a atingir 100% em alguns casos, o que levou à criação de uma ferramenta de code completion para guiar os programadores na utilização de uma API desconhecida, mas mantendo a possibilidade de a explorar