Contexts for ‘pure’ mathematics: a framework for analysing A-level mathematics papers

The use of context in mathematics test items is now accepted practice in many forms of national assessment in the UK. Yet research suggests that such use of context is not straightforward and that children may apply a variety of interpretations to contextual mathematics problems. Our analysis focuses on the use of context in post-16 ‘pure’ mathematics questions set by two UK Examination Boards. From our analysis, a framework for analysing the use of context is proposed that encompasses issues such as accessibility, realism and authenticity

The Extremes of the P/E Effect

The price-earnings effect has been a challenge to the idea of efficient markets for many years. The P/E used has always been the ratio of the current price to the previous year’s earnings. However, the P/E is partly determined by outside influences, such as the year in which it was measured, the size of the company, and the sector in which the company operates. Looking at all UK companies since 1975, we determine the power of these influences, and find that the sector influences the P/E in the opposite direction to the others. We use a regression to weight the influences according to their power in predicting returns, reversing the sector influence so that it works for us and not against us. The resulting weighted P/E widens the gap in annual returns between the value and glamour deciles by 8%, and identifies a value decile with average returns of 32%.

Decomposing the P/E Ratio

The price-earnings effect has been a challenge to the idea of efficient markets for many years. The P/E used has always been the ratio of the current price to the previous year’s earnings. However, the P/E is partly determined by outside influences, such as the year in which it was measured, the size of the company, and the sector in which the company operates. Looking at all UK companies since 1975, we determine the power of these influences, and find that the sector influences the P/E in the opposite direction to the others. We use a regression to weight the influences according to their power in predicting returns, reversing the sector influence so that it works for us and not against us. The resulting weighted P/E widens the gap in annual returns between the value and glamour deciles by 8%, and identifies a value decile with average returns of 32%.

The Long-Term P/E Radio

The price-earnings effect has been thoroughly documented and widely studied around the world. However, it has always been calculated on the basis of the previous year’s earnings. We show that the power of the effect has until now been seriously underestimated, due to taking too short-term a view of earnings. We look at all UK companies since 1975, and using the traditional P/E ratio we find the difference in average annual returns between the value and glamour deciles to be 6%, similar to other authors’ findings. We almost double that gap by calculating P/E ratios using earnings averaged over the last eight years. Averaging, however, implies equal weights for each past year. We widen the gap further by optimising the weights of the past years of earnings in the P/E ratio.

Knowledge-based system V and V in the Space Station Freedom program

Knowledge Based Systems (KBS's) are expected to be heavily used in the Space Station Freedom Program (SSFP). Although SSFP Verification and Validation (V&V) requirements are based on the latest state-of-the-practice in software engineering technology, they may be insufficient for Knowledge Based Systems (KBS's); it is widely stated that there are differences in both approach and execution between KBS V&V and conventional software V&V. In order to better understand this issue, we have surveyed and/or interviewed developers from sixty expert system projects in order to understand the differences and difficulties in KBS V&V. We have used this survey results to analyze the SSFP V&V requirements for conventional software in order to determine which specific requirements are inappropriate for KBS V&V and why they are inappropriate. Further work will result in a set of recommendations that can be used either as guidelines for applying conventional software V&V requirements to KBS's or as modifications to extend the existing SSFP conventional software V&V requirements to include KBS requirements. The results of this work are significant to many projects, in addition to SSFP, which will involve KBS's

Barriers to Workplace Advancement Experienced by Native Americans

Glass Ceiling ReportGlassCeilingBackground8NativeAmericans.pdf: 10836 downloads, before Oct. 1, 2020

The Excavation and Analysis of Prehistoric Caribbean Remains: A Bioarchaeological Case Study of a Prehistoric Female from Nevis, West Indies

ABSTRACT: The Excavation and Analysis of Prehistoric Caribbean Remains: A Bioarchaeological Case Study of a Prehistoric Female from Nevis, West Indies By Chris Keith In the summer of 2011, the remains of a 1000 year old indigenous Caribbean woman were discovered buried on a beach near White Bay, Nevis, West Indies. The following summer, a team of excavators and osteologists, including the author, returned to Nevis to excavate and analyze the remains with the intention to learn as much as possible about the remains and, through proxy, the people to whom they belonged. We felt that through our investigations of the life of this woman, whom we dubbed Taoüa, we would be able to extrapolate this information more broadly to the people living in the Caribbean during the Ostionoid period (circa 800-1150 Common Era, or CE). The research done on these remains is important since there is little known about migration patterns of the Caribbean people during the Ostionoid era, and there is much confusion about who was living where, and when, during this large swath of time. Beyond the wider academic appeal, there is much interest in Carib life by the modern Nevisians; in fact, this research was done in conjunction with the Nevisian Historical and Conservation Society (NHCS) and current Nevisians are eager to learn about the prior inhabitants, the history of the island, and what it meant to be a prehistoric Nevisian. The following paper is a catalog of the events of that trip, including excavation and analysis. A complete and detailed background of Caribbean prehistory will also be discussed in order to understand the cultural context of this individual. An additional literature review of osteological material will be undertaken to help draw correlations to the bony features we found on Taoüa and what activities, diet, and pathologies with which she may have been affected. Finally, the paper will conclude with a discussion of the analysis and the literary research

An Annotated Checklist of the Crayfishes (Decapoda: Cambaridae) of Arkansas

Prior to the present study, 56 species with 3 additional subspecies for a total of 59 different taxa of crayfishes were recognized from Arkansas. We add a single species (Carmel Crayfish, Fallicambarus schusteri) to that list, subtract a documented synonym (Procambarus ferrugenius = Procambarus liberorum), update the classification to better reflect recent phylogenetic insights, and provide an updated annotated checklist of the 59 crayfish taxa of presently known from the state. There are 8 endemic species in Arkansas, including the Bayou Bodcau Crayfish (Bouchardina robisoni), Boston Mountains Crayfish (Cambarus causeyi), Hell Creek Cave Crayfish (C. zophonastes), Jefferson County Crayfish (Creaserinus gilpini), Ouachita Burrowing Crayfish (Fallicambarus harpi), Slenderwrist Burrowing Crayfish (F. petilicarpus), Saline Burrowing Crayfish (F. strawni), and Redspotted Stream Crayfish (Faxonius acares). There are also 2 federally endangered species, the Benton County Cave Crayfish (Cambarus aculabrum) and the Hell Creek Cave Crayfish (C. zophonastes) that inhabit Arkansas karst habitat. We expect that additional species will be included in the list with further DNA analyses