ABC News/Washington Post Monthly Poll, March 2009

ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection: Standardized missing values.; Created online analysis version with question text.; Performed recodes and/or calculated derived variables.; Checked for undocumented or out-of-range codes..

ICPSR会对所有数据集开展保密审查，并在必要时对数据进行修改以降低数据泄露风险。此外，ICPSR还会常规生成开箱即用的数据文件，配套主流统计软件格式的程序配置文件，以及随数据一同提供的标准代码手册。除上述常规流程外，ICPSR针对本次数据集执行了以下处理步骤：
1. 完成缺失值标准化处理；
2. 创建附带问题文本的在线分析版本；
3. 执行变量重编码及（或）衍生变量计算；
4. 核查无文档说明的编码及超出取值范围的编码。