SPSS indicates that filtering is on in the status bar, and shows cases that aren't select in the Data Editor by putting a stroke through the case number. To turn case selection off, go back into the Select Cases dialog box and choose the Select All Cases option. Case filtering information is not retained when the file is saved. The Weight command under the Data menu allows you to weight cases by a frequency variable. The frequency values may be fractional.
Weighting is useful for certain types of analyses.
The Merge command lets you combine cases from two files or add variables to an existing set of cases. The Aggregate command allows you to summarize data for subgroups in the data file or for the entire data file. This is useful for producing aggregate reports or performing analysis on the aggregated data. The Transpose command allows you to transpose cases and variables, which is sometimes necessary when data has been entered with cases across columns instead of rows.