IBM SPSS Complex Samples

Work efficiently and easily with complex sample survey results

Only IBM® SPSS® Complex Samples makes understanding and working with your complex sample survey results easy. Through the intuitive interface, you can analyze data and interpret results. Choose from one of several wizards to make it easier to create plans, analyze data and interpret results.

When you're finished, you can publish public-use datasets and include your sampling and analysis plans. These plans act as a template and allow you to save all the decisions made when creating the plan – define it once and you're done. This saves time and improves accuracy for yourself and others who may want to plug your plans into the data to replicate results or pick up where you left off.

Use the following types of sample design information with IBM SPSS Complex Samples:

• Stratified sampling – Increase the precision of your sample or ensure a representative sample from key groups by choosing to sample within subgroups of the survey population.
• Clustered sampling – Select clusters, which are groups of sampling units, for your survey. Clustering often helps makes surveys more cost-effective.
• Multistage sampling – Select an initial or first-stage sample based on groups of elements in your population; then create a second-stage sample by drawing a sub-sample from each selected unit in the first-stage sample. By repeating this option, you can select a higher-stage sample.

Everything You Need for Planning

To help you through the planning stage in the analytical process, IBM SPSS Complex Samples provides you with specialized tools and procedures for working with sample survey data:

• IBM SPSS Complex Samples Plan (CSPLAN) – Use this procedure to specify the sampling frame to create a complex sample design or analysis specification used by companion procedures in IBM SPSS Complex Samples.
• Sampling Plan Wizard – If you are creating your own samples, use the Sampling Plan Wizard to define the scheme and draw the sample.
• Analysis Preparation Wizard – If you're using public-use datasets that already have samples, use the Analysis Plan Wizard to specify how the samples were defined and how standard errors should be estimated.
• Plan files – Once you have created plan files, you can save them and treat them as templates. This allows you to save all the decisions you made when creating the plan. This saves time and improves accuracy for yourself and others who may want to plug your plans into the data to replicate results or pick up where you left off.

Everything You Need for Data Management

IBM SPSS Complex Samples provides what you need for the data management stage when working with sample survey data. And it easily plugs into other IBM SPSS Statistics modules so you can seamlessly work in the IBM SPSS Statistics environment.

IBM SPSS Complex Samples Selection (CSSELECT) procedure -- Enables you to select complex, probability-based samples from a population while mitigating the risk in doing so (e.g. over- or under-representing a subgroup). CSSELECT chooses units according to a sample design created through the CSPLAN procedure.

With this procedure, you can:

• Control the scope of execution and specify a seed value with the CRITERIA subcommand
• Control whether or not user-missing values of classification (stratification and clustering) variables are treated as valid variables with the CLASSMISSING subcommand
• Specify general options concerning input and output files with the DATA subcommand
• Write sampled units to an external file using an option to keep/drop specified variables
• Automatically save first-stage joint inclusion probabilities to an external file when the plan specifies a probability proportionate to size (PPS) without replacement (WR) sampling method
• Opt to generate text files containing a rule that describes characteristics of selected units