A "Partial Match" occurs when there are slight variations between the input data and the data in Plaid's external data sources — for example, a typo, or input that contains only part of the data in the external data source (e.g. "Knope" vs. "Knope-Wyatt").
Example: In Sandbox, if you search by the exact same name as the one contained in the test record, you will get a match on name. Include a typo in the name input, and you will get a partial match. Use a completely different name, and you will get no match.
The same logic can be applied to any of the attributes. By modifying the sample record to use a search input, you should be able to simulate any outcome you'd like to test for.