Input spacing in second language classroom settings: Replications of Bird (2010) and Serrano (2011)

This paper proposes the replication of Bird's (2010) and Serrano's (2011) studies, which examined distribution of practice effects in second language acquisition (SLA). These studies, which took place in authentic classroom contexts, produced conflicting results regarding the degree to which the learning of a second language (L2) benefited from distributed instruction. In the first part of the paper, I discuss the distribution of practice research in the learning and teaching of L2s. I then describe Bird's (2010) and Serrano's (2011) work, and highlight the strengths and limitations of the approaches of these studies. Finally, a number of approaches to approximate replications are suggested for each study in order to assess the reliability, internal validity, and generalizability of the original findings

MICROTHREADING A MODEL FOR DISTRIBUTED INSTRUCTION-LEVEL CONCURRENCY

This paper analyses the micro-threaded model of concurrency making comparisons with both data and instruction-level concurrency. The model is fine grain and provides synchronisation in a distributed register file, making it a promising candidate for scalable chip-multiprocessors. The micro-threaded model was first proposed in 1996 as a means to tolerate high latencies in data-parallel, distributed-memory multi-processors. This paper explores the model's opportunity to provide the simultaneous issue of instructions, required for chip multiprocessors, and discusses the issues of scalability with regard to support structures implementing the model and communication in supporting it. The model supports deterministic distribution of code fragments and dynamic scheduling of instructions from within those fragments. The hardware also recognises different classes of variables from the register specifiers, which allows the hardware to manage locality and optimise communication so that it is both efficient and scalable.