Import data from SAS and SPSS
With Stata 16’s new import sas and import spss commands, you can now import data stored in SAS (.sas7bdat) and SPSS (.sav) formats. The dialog boxes make it easy to explore the data before importing them and, if desired, to select a subset of variables and observations to load into Stata.
In addition, with the new import sasxport8 and export sasxport8 commands, you can import and export SAS XPORT Version 8 Transport files into Stata. The existing import sasxport and export sasxport commands worked with SAS XPORT Version 5 Transport files and have been renamed import sasxport5 and export sasxport5.
2019年12月下旬，Stata正式推出中文版本。如果您的电脑语言是中文，那么Stata会自动识别为中文版。Windows和Unix系统可手动更改语言版本，Edit > Preferences > User-interface language，如果是Mac系统，可通过Stata 15 > Preferences > User-interface language手动更改版本语言。
Stata是一款完整的、集成的统计软件包，提供您需要的一切数据分析、数据管理和图形。
快速,简单并易于使用
点击式的界面和强大,直观的命令语言让Stata使用起来快速,精确并易于使用。
所有的分析结果都可以被复制和存档，并用来出版和审查。不管您什么时候写的内容，版本控制系统确保统计程序可继续生成同样的结果。
统计功能介绍
Stata使得大量的统计工具用于指尖
标准方法，如
基本表格和总结
案例对照分析
ARIMA
ANOVA 和MANOVA
线性回归
时间序列平滑
广义线性模型（GLM）
聚类分析
对比和比较
功率分析
样本选择
……
高级方法，如
多层模型
生存分析
动态面板数据回归
结构方程建模
二进制，计数和审查结果
ARCH
多重替代法
调查数据
Treatment effects
精确统计
贝叶斯分析
……
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Multiple-group IRT models in Stata
IRT models explore the relationship between a latent (unobserved) trait and items that measure aspects of the trait. This often arises in standardized testing where the trait of interest is ability, such as mathematical ability. A set of items (test questions) is designed, and the responses measure this unobserved trait. Researchers in education, psychology, and health frequently fit IRT models.
Stata’s irt commands fit 1-, 2-, and 3-parameter logistic models. They also fit graded response, nominal response, partial credit, and rating scale models, and any combination of them. And after fitting a model, irtgraph graphs item-characteristic curves, test characteristic curves, item information functions, and test information functions.
New in Stata 16, the irt commands allow comparisons across groups. Take any of the existing irt commands, add a group(varname) option, and fit the corresponding multiple-group model. For instance, type
. irt 2pl item1-item10, group(female)
and fit a two-group 2PL model.
Group-specific means and variances of the latent trait will be estimated. Group-specific difficulty and discrimination parameters can also be estimated for one or more items. With constraints, you can specify exactly which parameters are allowed to vary and which parameters are constrained to be equal across groups.
You can even use likelihood-ratio tests to compare models with and without constraints to perform an IRT model-based test of differential item functioning.
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