A Longitudinal Study on Stability and Transitions Among Bullying Roles

Trajectories of stability and change in bullying roles were examined through a longitudinal prospective study of 916 school students followed up biannually from age 11 to 17. Perpetrators and victims had relatively stable trajectories with most of the children remaining in the same role over time or becoming uninvolved. Bully/victim was the most unstable role with frequent transitions to perpetrators or victims. Developmental change in bullying roles was found with a decrease in physical forms over time in bullies and victims but with persistently high perpetration and victimization in bully/victims. These findings open new horizons in research and practice related to bullying and can be useful for its early detection or design of targeted interventions.     

A compressed self-index using a Ziv–Lempel dictionary

A compressed full-text self-index for a text T, of size u, is a data structure used to search for patterns P, of size m, in T, that requires reduced space, i.e. space that depends on the empirical entropy (H _k or H ₀) of T, and is, furthermore, able to reproduce any substring of T. In this paper we present a new compressed self-index able to locate the occurrences of P in O((m + occ)log u) time, where occ is the number of occurrences. The fundamental improvement over previous LZ78 based indexes is the reduction of the search time dependency on m from O(m ²) to O(m). To achieve this result we point out the main obstacle to linear time algorithms based on LZ78 data compression and expose and explore the nature of a recurrent structure in LZ-indexes, the suffix tree. We show that our method is very competitive in practice by comparing it against other state of the art compressed indexes.

Morphological priming effects on children’s spelling

Previous research has suggested that children in the early grades of primary school do not have much awareness of morphemes. In this study, a priming paradigm was used to try to detect early signs of morphological representation of stems through a spelling task presented to Portuguese children (N = 805; age range 6–9 years). Primes shared the stem with the targets and contained well-articulated, stressed vowels; the stems of the target words and pseudo-words contained non-stressed schwa vowels, which typically result in spelling difficulties. If priming proved effective, the well-articulated vowels in the prime should result in an improvement in the spelling of the schwa vowels. Primes were presented in two conditions: in only-oral or in oral-plus-written form. Effectiveness of priming was assessed by comparison with a no-priming condition. For both words and pseudowords, there was a significant interaction between priming effects and grade. No priming effects were detected in 6- and 7-year-old children; oral-plus-written priming produced higher rates of correct vowel spelling for 8- and 9-year-olds; only-oral priming was effective in improving the vowel spelling of 9-year-olds. Thus older children can use morphological information under priming conditions when the prime and the target are not phonologically transparent but there is no evidence to suggest that younger children do so.     

The chimera of the competency-based approach to teaching mathematics: a study of carpentry purchases for home projects

Educational Studies in Mathematics - The competency-based approach conceives mathematics as a necessary tool for dealing with daily-life tasks. Many studies have focused on examining the low math...     

Factors influencing adaptation from university to employment in Portugal and Brazil

International Journal for Educational and Vocational Guidance - The career adaptation model helps to explain the process of transitioning from university to employment among college students. This...     

How to Assess and Categorize Teachers’ Views of Science? Two Methodological Issues

Research in Science Education - This paper addresses two methodological issues related to the assessment of teachers’ views of science. The first concerns the distinction between the...     

The Use of Different Translation Devices to Analyze Knowledge-Building in a University Chemistry Classroom

Research in Science Education - This research draws on Legitimation Code Theory (LCT) to understand the epistemic dimension of the higher education classroom discourse of a professor who is well...