Combining data files with the Append node

Similar pieces of information for different groups of records may be stored in different data files. There is often a need to collectively analyze such data, possibly to compare performance over subsequent years or to discover group differences. To analyze such information within Modeler, the data files must be combined into one single file. The Append node joins two or more data sources together so that information held for different groups of records can be analyzed and compared. The following diagram depicts how the Append node can be used to combine two separate data files that contain similar information:

Let's go through an example of how to use the Append node to combine data files:

1. Open the Append stream.
2. Run a Table node from each source node so that you are familiar with each data file (not shown).

Notice the number of cases in each file. Also notice that one file has financial data for 1994 while the second file has financial data for 1995...