Optimal coding and the origins of Zipfian laws

The problem of compression in standard information theory consists of assigning codes as short as possible to numbers. Here we consider the problem of optimal coding -- under an arbitrary coding scheme -- and show that it predicts Zipf's law of abbreviation, namely a tendency in natural languages for more frequent words to be shorter. We apply this result to investigate optimal coding also under so-called non-singular coding, a scheme where unique segmentation is not warranted but codes stand for a distinct number. Optimal non-singular coding predicts that the length of a word should grow approximately as the logarithm of its frequency rank, which is again consistent with Zipf's law of abbreviation. Optimal non-singular coding in combination with the maximum entropy principle also predicts Zipf's rank-frequency distribution. Furthermore, our findings on optimal non-singular coding challenge common beliefs about random typing. It turns out that random typing is in fact an optimal coding process, in stark contrast with the common assumption that it is detached from cost cutting considerations. Finally, we discuss the implications of optimal coding for the construction of a compact theory of Zipfian laws and other linguistic laws.Comment: in press in the Journal of Quantitative Linguistics; definition of concordant pair corrected, proofs polished, references update

Decoding the Brain: Neural Representation and the Limits of Multivariate Pattern Analysis in Cognitive Neuroscience

Since its introduction, multivariate pattern analysis (MVPA), or “neural decoding”, has transformed the field of cognitive neuroscience. Underlying its influence is a crucial inference, which we call the Decoder’s Dictum: if information can be decoded from patterns of neural activity, then this provides strong evidence about what information those patterns represent. Although the Dictum is a widely held and well-motivated principle in decoding research, it has received scant philosophical attention. We critically evaluate the Dictum, arguing that it is false: decodability is a poor guide for revealing the content of neural representations. However, we also suggest how the Dictum can be improved on, in order to better justify inferences about neural representation using MVPA

A survey of Western Australian teachers’ use of texts in supporting beginning readers

Connected text reading is crucial to beginning reading development as this is where children apply the reading skills they are learning. The most recent version of the Australian Curriculum includes the requirement that teachers use both predictable and decodable texts in early reading instruction. As each text type is underpinned by a different approach to reading instruction, this creates a potential dilemma for teachers when implementing the curriculum. A preliminary study of the instructional practices used to teach reading in the first two years of schooling was therefore conducted to investigate how early years teachers make use of two different text types that are arguably incompatible. An online survey regarding approaches to reading instruction and use of different text types was distributed to Western Australian Pre-primary and Year 1 teachers via several social media platforms. A total of 138 teachers responded. Survey responses indicated that these teachers do not have a coherent understanding of the purpose of different text types in beginning reading instruction. The findings highlight the need to improve early years teachers’ knowledge of the instructional strategies aligned to each text type so that they can make informed decisions when supporting children’s reading development

Concatenated Quantum Codes Constructible in Polynomial Time: Efficient Decoding and Error Correction

A method for concatenating quantum error-correcting codes is presented. The method is applicable to a wide class of quantum error-correcting codes known as Calderbank-Shor-Steane (CSS) codes. As a result, codes that achieve a high rate in the Shannon theoretic sense and that are decodable in polynomial time are presented. The rate is the highest among those known to be achievable by CSS codes. Moreover, the best known lower bound on the greatest minimum distance of codes constructible in polynomial time is improved for a wide range.Comment: 16 pages, 3 figures. Ver.4: Title changed. Ver.3: Due to a request of the AE of the journal, the present version has become a combination of (thoroughly revised) quant-ph/0610194 and the former quant-ph/0610195. Problem formulations of polynomial complexity are strictly followed. An erroneous instance of a lower bound on minimum distance was remove

The influence of teachers’ knowledge and teaching practice on outcomes for beginning readers : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Education at Massey University, Manawatū Campus, New Zealand

New Zealand has a problem with reading achievement, in spite of ongoing efforts to address the issue. The current study selected to investigate the influence of teachers’ knowledge and teaching practice in teaching beginning reading. The study was a two-phase, mixed methods, explanatory sequential design, involving 30 teachers from 12 urban, state schools located in New Zealand’s lower North Island. Teachers participated in professional learning and development (PLD) workshops focused on teacher knowledge and explicit teaching practice for beginning readers. The study used data from 109 New Entrant children from the PLD classrooms and from a non-PLD comparison group of 61 new entrant children. The first phase of the study involved obtaining and analysing data about teachers’ linguistic knowledge, self-confidence for teaching literacy, teaching practice, and reading prompts. The data were analysed using descriptive statistics and t-tests. The findings showed that teachers’ knowledge of linguistic constructs and self-confidence in teaching the code component of reading increased significantly. Observations showed a significant change in teaching practice, from implicit teaching to explicit teaching. Teachers’ prompts changed significantly to using code-cue prompts. For some teachers, teaching practice remained implicit and prompts remained context-based, regardless of an increase in their teacher knowledge. The second phase of the study involved interviews with four teachers to identify barriers for teachers in changing to explicit teaching. Student reading skills were measured and data analysed using a series of MANOVAs and ANOVAs to identify any differences between the implementation and comparison groups. The student data showed significantly better outcomes for the implementation students, with a notable positive difference for students from schools located in lower socio-economic neighbourhoods. Findings suggest that when teachers are equipped with knowledge and practice to teach the code component explicitly to beginning readers, improvement in reading outcomes is possible. Recommendations from the study include that changes are required at a policy level, in teacher training, and for teaching resources, with a particular need for increased cognisance of studies from the science of reading.

Evolution of modern literature and film

The evolution of complex narratives, such as fictional books or films, is a fairly new area of cultural-evolutionary research. This chapter, first, discusses a theoretical question: in what sense do narratives evolve? Then, it proceeds to describing how content-based, or hedonic, selection influences the evolution of narrative forms – and briefly, the role of several other evolutionary mechanisms, such as drift and accumulation of innovations. Finally, the chapter presents the methods used for studying the evolution of literature and film at a large scale: from manual coding to various computational techniques.Introduction Narratives evolve Hedonic selection of stories Beyond Selection: Drift, Cumulation, Co-evolution Books and films as data Conclusio