308 research outputs found
The Effects of Home Computers on Educational Outcomes: Evidence from a Field Experiment with Schoolchildren
Are home computers are an important input in the educational production
function? To address this question, we conduct a field experiment
involving the provision of free computers to schoolchildren for home
use. Low-income children attending middle and high schools in 15 schools
in California were randomly selected to receive free computers and
followed over the school year. The results indicate that the experiment
substantially increased computer ownership and total computer use among
the schoolchildren with no substitution away from use at school or other
locations outside the home. We find no evidence that the home computers
improved educational outcomes for the treatment group. From detailed
administrative data provided by the schools and a follow-up survey, we
find no evidence of positive effects on a comprehensive set of outcomes
such as grades, test scores, credits, attendance, school enrollment,
computer skills, and college aspirations. The estimates also do not
indicate that the effects of home computers on educational outcomes are
instead negative. Our estimates are precise enough to rule out even
modestly-sized positive or negative impacts. The lack of a positive net
effect on educational outcomes may be due to displacement from
non-educational uses such as for games, social networking, and
entertainment. We find evidence that total hours of computer use for
games and social networking increases substantially with having a home
computer, and increases more than total hours of computer use for schoolwork
Home media and science performance:A cross-national study
This study examines the effects of media resources in the parental home on the science performance of 15-year-old students. It employs data from the 2006 Programme for International Student Assessment (PISA) containing information on 345,967 respondents from 53 countries. Results show that media assets in the family home are indeed meaningful for children’s science performance, as a beneficial resource but also as a disadvantage. A positive reading climate in the parental home and the availability of computers benefits science performance. However, a television-rich home seems to hinder children’s school success. Furthermore, results indicate that, compared to less developed countries, in more modernized societies parental reading investments are even more beneficial to their children’s science performance, whereas a television-rich parental home is even more disadvantageous
A modified empirical criterion for strength of transversely anisotropic rocks with metamorphic origin
A modified empirical criterion is proposed to determine the strength of transversely anisotropic rocks. In this regard, mechanical properties of intact anisotropic slate obtained from three different districts of Iran were taken into consideration. Afterward, triaxial rock strength criterion introduced by Rafiai was modified for transversely anisotropic rocks. The criterion was modified by adding a new parameter α for taking the influence of strength anisotropy into consideration. The results obtained have shown that the parameter α can be considered as the strength reduction parameter due to rock anisotropy. The modified criterion was compared to the modified Hoek–Brown (Saroglou and Tsiambaos) and Ramamurthy criteria for different anisotropic rocks. It was concluded that the criterion proposed in this paper is a more accurate and precise criterion in predicting the strength of anisotropic rocks
Avoidable mortality across Canada from 1975 to 1999
BACKGROUND: The concept of 'avoidable' mortality (AM) has been proposed as a performance measure of health care systems. In this study we examined mortality in five geographic regions of Canada from 1975 to 1999 for previously defined avoidable disease groups that are amenable to medical care and public health. These trends were compared to mortality from other causes. METHODS: National and regional age-standardized mortality rates for ages less than 65 years were estimated for avoidable and other causes of death for consecutive periods (1975–1979, 1980–1985, 1985–1989, 1990–1994, and 1995–1999). The proportion of all-cause mortality attributable to avoidable causes was also determined. RESULTS: From 1975–1979 to 1995–1999, the AM decrease (46.9%) was more pronounced compared to mortality from other causes (24.9%). There were persistent regional AM differences, with consistently lower AM in Ontario and British Columbia compared to the Atlantic, Quebec, and Prairies regions. This trend was not apparent when mortality from other causes was examined. Injuries, ischaemic heart disease, and lung cancer strongly influenced the overall AM trends. CONCLUSION: The regional differences in mortality for ages less than 65 years was attributable to causes of death amenable to medical care and public health, especially from causes responsive to public health
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