This work presents the analysis of the 2001 Brazilian Basic Education Evaluation System (SAEB) achievement exam. The SAEB tested 4th, 8th, and 11th grade students, in mathematics and reading (Portuguese). We classified the students into seven socioeconomic classes, and for each class, compared the test results according to frequency of computer use, computer ownership, Internet access at home, and whether the teachers used computers and Internet as pedagogical tools. Frequency of computer use had, in general, a negative effect on the test results, and the negative effect increased for younger and poorer students. Computer ownership had, in general, a small positive effect on the test results for older students, and no effect for 4th graders. Internet access had a negative effect for younger and poorer students, and a positive effect for 11th graders. Finally, whether the teacher used computers or Internet as pedagogical tools had no effect on the student's test results for all social economic classes and grades.

RESUMO:As políticas públicas de educação têm dado bastante ênfase, ao longo dos últimos anos, à necessidade de informatizar as escolas e modificar práticas de ensino devido ao advento da sociedade de informação. Este artigo usa as pesquisas do SAEB para verificar o desempenho de alunos de 4ª e 8ª série do ensino fundamental e da 3ª série do ensino médio e a relação deste desempenho com o uso de computador. Os resultados demonstram que para os alunos de todas as séries e para todas as classes sociais o uso intenso do computador diminui o desempenho escolar. Para alunos da 4ª série, das classes sociais mais pobres, mesmo o uso moderado do computador piora o desempenho nos exames de português e matemática. Esses resultados indicam claramente que é preciso repensar o papel do computador no ensino, sobretudo para os alunos mais pobres, para quem o uso do computador está surpreendentemente associado a uma piora nas suas notas. Palavras-chave:Computadores. Educação fundamental. Educação média. Desempenho. SAEB. REVEALING MYTHS: COMPUTERS AND SCHOOL PERFORMANCEABSTRACT: Over the last few years, public educational policies have had an emphasis on the need to equip schools with computers * Dwyer (livre-docente), Magalhães (doutorando) e Ferreira (doutorando) são do Instituto de Filosofia e Ciências Humanas da UNICAMP; Wainer (livre-docente), Covic (mestrando) e Pimenta

An assessment of four linear‐system iterative solvers is carried out through the simulation of a key 2D photonic crystal structure. Among these solvers, the biconjugate gradient stabilized (BCGS) in conjunction with the incomplete LU (ILU) decomposition, shows the best performance and can be regarded as a promising candidate for large‐scale computation. In addition, the iterative solver with the best performance is applied to analysis of the directional optical coupler and transverse anisotropic waveguide. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1182–1186, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21571