Normally, when you have a dataset query which is filtered by a parameter (like the one below), it's easy to test it in the query design tool:

SELECT field1,field2 FROM table WHERE field3 = @someParameter

...you simply click the "!" button on the toolbar, and a Query Parameter dialog pops up in which you specify the value for @someParameter. However, what can you do if you're using a multi-value parameter and therefore need to provide a set of values:

...WHERE field3 IN (@someParameter)

You might want to pass a series of values, like ('cat', 'dog'), etc. Well, there's unfortunately no good way to do this. The query design tool is based on SQL Server functionality which doesn't natively support multi-value parameters. I guess you could temporarily hard-code a few values directly inside your search condition (IN list), but that's about it. Bummer!