Evaluating Forecasting Methods

Ideally, forecasting methods should be evaluated in the situations for which they will be used. Underlying the evaluation procedure is the need to test methods against reasonable alternatives. Evaluation consists of four steps: testing assumptions, testing data and methods, replicating outputs, and assessing outputs. Most principles for testing forecasting methods are based on commonly accepted methodological procedures, such as to prespecify criteria or to obtain a large sample of forecast errors. However, forecasters often violate such principles, even in academic studies. Some principles might be surprising, such as do not use R-square, do not use Mean Square Error, and do not use the within-sample fit of the model to select the most accurate time-series model. A checklist of 32 principles is provided to help in systematically evaluating forecasting methods

Like mother, like child : investigating perinatal and maternal health stress in post-medieval London.

Post-Medieval London (sixteenth-nineteenth centuries) was a stressful environment for the poor. Overcrowded and squalid housing, physically demanding and risky working conditions, air and water pollution, inadequate diet and exposure to infectious diseases created high levels of morbidity and low life expectancy. All of these factors pressed with particular severity on the lowest members of the social strata, with burgeoning disparities in health between the richest and poorest. Foetal, perinatal and infant skeletal remains provide the most sensitive source of bioarchaeological information regarding past population health and in particular maternal well-being. This chapter examined the evidence for chronic growth and health disruption in 136 foetal, perinatal and infant skeletons from four low-status cemetery samples in post-medieval London. The aim of this study was to consider the impact of poverty on the maternal-infant nexus, through an analysis of evidence of growth disruption and pathological lesions. The results highlight the dire consequences of poverty in London during this period from the very earliest moments of life

Evolução histórica dos utensílios empregados para alimentar lactentes não amamentados Historical evolution of utensils used to feed non breastfed infants

O objetivo desse artigo de revisão é descrever os utensílios empregados ao longo da história para alimentar lactentes não amamentados. O levantamento bibliográfico foi realizado nas bases de dados MEDLINE, LILACS e SciELO, de 1966 a 2007. Para a análise documental, foram processadas buscas na Internet, em enciclopédias, livros de arte, história e museus. Utensílios manufaturados com materiais e formas variadas, dependendo da disponibilidade, poder aquisitivo e cultura, foram empregados desde os primórdios da história para alimentar bebês que, por diferentes motivos, deixaram de ser amamentados. Muitos objetos coexistiram na mesma época e local, outros em tempos e pontos geográficos distantes. A aceitação de uma nova alternativa ocorria sem evidência que comprovasse ou apontasse para os benefícios da mudança. Alguns utensílios voltaram a ser empregados embora a mortalidade infantil fosse elevada à época em que foram utilizados. No início do século XX, as mamadeiras assumiram a forma cilíndrica cônica. A tecnologia trouxe avanços no sentido de melhorar a higienização e possibilitar o controle da contaminação. O vidro deu lugar ao plástico e os bicos de borracha, aos de silicone, mas a mamadeira, como a conhecemos hoje, é a mesma de cem anos atrás.<br>The objective of this article is to describe the utensils used throughout history to feed non breastfed infants. The method used was article review, reference search on the MEDLINE, LILACS and SciELO databases from 1966 to 2007 and documental analysis based on data from the internet, encyclopedias, art and history books, and museums. Utensils manufactured in a variety of materials and shapes, depending on availability, purchasing power and culture have been used since early history to feed babies who for different reasons were not breastfed. Many objects coexisted at the same time and place, others at distant sites and times. New alternatives have been accepted without evidence to prove or point toward the benefits of the change. Some of these alternatives were adopted again, even if infant mortality was high at the time in which they were used at first. In the beginning of the 20th century, bottles became conic-cylindrical. Technology brought about progress as to improve hygiene and enable contamination control. Glass gave way to plastic, and rubber nipples to silicone ones, but the bottle as we know it today is still the same of a 100 years ago