There are two main parts to data correlation. One part occurs during test generation and script editing, and the other part occurs during script execution.
The test generation part of data correlation is the most significant part. There is automatic data correlation that is performed during test generation, and there is manual correlation that can be performed during script editing. There are several different things that can be done as part of manual correlation: you can substitute values into a site from a data pool, a built-in data source, or a reference that is already created.
For more details about test generation extensibility, see the "Extending the test generator" topic. For details about the Script class, see the "Extending code generation" topic.
For examples of data correlation extensions, see these plug-ins: com.ibm.rational.test.lt.sdksamples.datacorrelation.testgen.socket com.ibm.rational.test.lt.sdksamples.datacorrelation.execution.socket