医学科研数据分析与教学中的基本问题

Basic aspects of data analysis and teaching in medical scientific research

统计分析包括统计描述和统计推断。统计描述包括对数据集中趋势、离散趋势、抽样误差以及分布特征等进行描述。统计描述的关键是如何正确选择有关的统计量，其主要取决于3个要素：描述样本哪方面特征、资料类型、数值分布特征；其次，要注意统计量的合理搭配使用以及联合使用。统计推断包括参数估计和假设检验两个方面。参数估计指由样本统计量估计总体参数，通常用区间估计方法；大多数假设检验方法的正确选用受6个因素的影响，包括研究目的、研究因素的多少、组数或研究的水平数、实验设计类型、资料类型与分布特征以及样本含量大小。

Statistical analysis includes statistical description and inference. The former one describes central and dispersion tendency, sampling error and characteristics of data distribution. The key of statistical description is how to properly select the relevant statistic which primarily depends on three elements： characteristics of sample, type of data and its characteristics of distribution. Secondly, we should pay attention to correct matching and combination use of statistics. Statistical inference includes parameter estimation and hypothesis testing. We usually use interval estimation to do parameter estimation. The correct selection of the methods of hypothesis testing needs the following six factors, research purpose, number of research factors, number of groups or research level, types of experiment design, data types and distribution characteristics, and the sample size.