Conducting process-product studies : some considerations

One of the major factors which deter mines the validity of research findings is undoubtedly the effectiveness of the decision-making process in setting up a design and a general methodology which are both rigorous and compatible with the aims of the study. Indeed, all the decisions made, be they major or minor ones, and related problems, vary from one study to the next depending largely on the nature and purpose of the exercise. The great majority of decisions required in designing a study are made in its early stages, It is usually the case, however, that in the course of a study other decisions would have to be taken. Since most decisions are interrelated, a change in one would precipitate a change in, or a reconsideration of, at least a second decision. Vis-a-vis the above, it is the purpose of this paper to discuss some of the aspects and issues which should be considered in a research study of the relationship between teaching and attainment. Although most of the following arguments and considerations would be valid for such a study at the primary or secondary level of education, these would be more true at the former level.peer-reviewe

Sex differences in scholastic attainment from year 3 to form IV : a study of trends

The role of pupil sex as one of the major determinants of scholastic performance is amply demonstrated in the international literature. Studies of primary school children carried out in the UK and the USA generally indicate that whatever sex differences exist in scholastic performance these tend to emerge clearly and consistently after age 11 (cf. Badger, 1985; Fairweather, 1976; Shackleton & Fletcher, 1984; Shuard, 1982). Studies by Ross & Simpson (1971), Thompson (1975) and Wilson (1972), for instance, show that in verbal abilities like reading and spelling no clear cut boy-girl differences appear before this age. Studies by Kellmer Pringle, Butler & Davie (1966) and Pidgeon (1960) similarly suggest that this is also the case for arithmetic skills and mathematical ability. In a comprehensive review of the literature on sex differences, Maccoby & Jacklin ( 197 4) conclude that up to age 11 boys and girls are very similar in verbal and mathematical abilities. At age 11, however, their abilities begin to diverge with girls becoming superior in verbal abilities and boys in mathematical abilities. Borg & Falzon (1995) propose a plausible explanation for the little or no consistency in the occurrence and direction of sex differences. They argue that this may lie in the nature of the items making up the assessment instrument. Indeed, in a report on mathematical performance at age 11, the Assessment of Performance Unit (1980) found that when the examination paper is analysed in its component parts rather than as a whole paper girls perform significantly better than boys in certain areas such as computation while boys perform better in other areas like the spatial (e.g. length , area, volume and capacity). Borg & Falzon ( 1995) postulate that this may also well be the case in language subjects so that it is quite possible, for instance, to find girls performing better in one specific language area and boys in another. Hence, differ- ences and directions may well be the product of the weighting of the various abilities assessed by the instrument. Although these UK and USA findings on sex differences may be important and interesting and may have serious implications for educational policies and practices it is here argued that they are not, or should be, directly transferable to the local situation. Cultural differences as well as differences in parental practices, educational philosophies and classroom practices warrant that sex differences in performance in school subjects should be studied in the local context. A small number of Maltese studies have begun to address this need. Falzon & Sammut (1976), for instance, found that amongst Maltese Form I and Il pupils in comprehensive schools girls consistently score higher in Maltese, English, and Maths, with the greatest differences occurring ip the two languages. Moreover, Ventura (1992) reports that whereas in Forms I and II girls outperform boys in Integrated Science, in Forms Ill and IV there are no sex differences in performance in Biology and Chemistry; in Physics, however, the boys perform better.peer-reviewe

Adaptive delayed channel access for IEEE 802.11n WLANs

Abstract— In this paper we investigate potential benefits that an adaptive delayed channel access algorithm can attain for the next-generation wireless LANs, the IEEE 802.11n. We show that the performance of frame aggregation introduced by the 802.11n adheres due to the priority mechanism of the legacy 802.11e EDCA scheduler, resulting in a poor overall performance. Because high priority flows have low channel utilization, the low priority flows throughputs can be amerced further. By introducing an additional delay at the MAC layer, before the channel access scheduling, it will retain aggregate sizes at higher numbers and consequently a better channel utilization. Also, in order to support both UDP and TCP transport layer protocols, the algorithm’s operational conditions are kept adaptive. The simulation results demonstrate that our proposed adaptive delayed channel access outperforms significantly the current 802.11n specification and non-adaptive delayed channel access

Binary morphological shape-based interpolation applied to 3-D tooth reconstruction

In this paper we propose an interpolation algorithm using a mathematical morphology morphing approach. The aim of this algorithm is to reconstruct the $n$-dimensional object from a group of (n-1)-dimensional sets representing sections of that object. The morphing transformation modifies pairs of consecutive sets such that they approach in shape and size. The interpolated set is achieved when the two consecutive sets are made idempotent by the morphing transformation. We prove the convergence of the morphological morphing. The entire object is modeled by successively interpolating a certain number of intermediary sets between each two consecutive given sets. We apply the interpolation algorithm for 3-D tooth reconstruction

Estimation of microscopic averages from metadynamics

With the help of metadynamics it is possible to calculate efficiently the free energy of systems displaying high energy barriers as a function of few selected "collective variables". In doing this, the contribution of all the other degrees of freedom ("microscopic" variables) is averaged out and, thus, lost. In the following, it is shown that it is possible to calculate the thermal average of these microscopic degrees of freedom during the metadynamics, not loosing this piece of information

Adsorption of atomic and molecular oxygen on Si(100)2x1: coverage dependence of the Auger O KVV lineshape.

By means of Auger electron spectroscopy (AES) we have monitored the room temperature adsorption of O2 and N2O on the clean Si(0 0 1)2 × 1 surface. We have found, for the first time, a significant variation in the intensity ratio of the K L1 L1 and K L23 L23 O Auger lines in the submonolayer range. This variation can be related to a change in bonding configuration of the oxygen atom/molecule in the initial adsorption stage in which the influence of inter-atomic matrix elements of the Auger process cannot be neglected