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Studying chemistry
Posted on May 6th, 2010 No commentsChemistry is an amazing and interesting subject, but a lot of students have big problem to learn it. In particular, some difficulties arise from abstract concepts that hardly can be applied to all days life.
Scientists from the University of Pittsburg set up a digital library of virtual activities in order to teach general chemistry and engage students in problem solving. The Chemcollective collects a list of information for both teachers and students. In teacher section there are activities based on fundamental concepts of general chemistry, such as stoichiometry, acid- basis, molarity and so on, and some free courses on stoichiometry. The special feature is the application of knowledge on real world problems: the arsenic contamination in Bangladesh may cause water pollution. Students have to determine how various powders absorb arsenic, or whether water is safe to drink. Based on this principle, students are engaged and stimulated to find out practical chemical solutions to proposed issues. In student section, a deepen tutorial summarizes the most important chemical concepts with simple and clear definitions. Simulations of experiments are also available in this section. In summary, this project allows students to love chemistry and better understand its peculiarity. -
Brain training is useless!
Posted on April 28th, 2010 No commentsCommercially available brain trainings are computerized tests, developed and marketed with the aim to improve cognitive functions in children and adults. Basically, the use of this software may improve memory, problem solving, measure of reasoning and verbal short-term memory.
Anyway, it has been noticed that in pre-school children video game players outperform not players in visual memory, but don’t have any other advantage in terms of cognitive improvement. To deepen this aspect, a large scale study has been carried out enrolling thousand of persons. Three study groups have been randomly assigned and each group has been trained on a specific task: the first one has been trained in planning and problem solving ability, the second one has been trained in a broader range of cognitive activities, from visual memory to attention, ad so on, the third group has to solve some general question by using every available source. This training lasts six weeks. At the end of the study statistical analyses reveal that each group have improved only in the specific task in which has been trained, but none general improvement of cognitive process in other task has been noticed. In conclusion, brain training tests don’t contribute to develop human mind. -
Statistics in science
Posted on January 29th, 2010 No commentsA common English quote says that there are three kinds of lies: lies, damned lies and statistics. This sentence was wrongly attributed to Disraeli, whereas it was firstly published by Marc Twain. Even if it could seem true, statistics is the only tool available up to date to manage a large amount of data and to give their a mean. Several functions are usually used in statistical analysis; the most common are the average, standard deviation, frequency and also the number of observation is reported in scientific publications.
All these data are defined as descriptive statistics because of their direct characterization of the population of interest. In other cases more complex calculations must be done to find significance from the study. Linear or logistic regressions are models to identify the trend that better explain and summarize the collected data. From linear or logistic regression is possible to interpolate or extrapolate data in order to predict results into the studied range or outside the studied range, respectively. Furthermore, from statistical analyses prevalence, incidence, absolute risk, odd ratio and relative risk are determined. All of these parameters are so important that must be determined during clinical study and are subsequently used to compare different protocols, drugs and so on. Clinical studies are classified as experimental studies or observational studies. The main difference between these two classes is the presence of a treatment given to patients in the experimental studies, whereas in the observational studies none treatment is followed but the selected population is just observed to determine the parameters of interest. In both cases, given the high number of patients enrolled in order to obtain significant results, statistics is useful to compare treated cohort and placebo cohort, for example, as well as to evaluate the role of specific component of the study, namely called covariates.
The major part of software that help to collect and manage data from a clinical study have also some algorithms to calculate standard statistical parameters during the data collection self. Revision and further elaboration must be done by professionals in order to correctly consider study results. Statistics is important not only in clinical trials, but also in all experiments performed in science. Indeed, to be sure to have obtained a result as a consequence of certain conditions and not due to serendipity, all experiments are usually repeated three or more times. Data presentation normally comprises average and standard deviation or confidence interval and significance is determined by a series of tests that should be described in material and methods section of the publication. In conclusion scientists must have some basis of statistics because this discipline confers value to their experiments and make them shareable and comparable with scientific community. Even if statistics is considered as a lie in some cases, it will be useful for science advances.
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