Humans exhibit characteristic success in considering what is relevant in their cognitive tasks. Yet understanding how relevance is determined in cognition remains a problem. This paper seeks to make headway on this problem. The relevance problem is first introduced. Sperber and Wilson’s influential theory of relevance is then discussed, but dismissed as inadequate. Some conditions are identifie...

Hadoop is currently the large-scale data analysis ‘‘hammer’’ of choice, but there exist classes of algorithms that aren’t ‘‘nails’’ in the sense that they are not particularly amenable to the MapReduce programming model. To address this, researchers have proposed MapReduce extensions or alternative programming models in which these algorithms can be elegantly expressed. This article espouses a ...

Many application systems make use of various forms of asynchronously updated replicas to improve scalability, availability and performance. If an application uses replicas that are not in sync with source data, it is clearly willing to accept results that are not completely current, but typically with some limits on how stale the data can be. Today, such requirements are not explicitly declared...