[rules-users] Parameterized Queries?

Does anyone know how to use parameterized queries? I'm trying to retrieve ONLY the results for a single installation, with a query like this: query "find errors for site" validationError: ValidationError(this.siteId == $1) end QueryResults results = session.getQueryResults("find errors for site", new Object[] {siteId}); I get the error "org.drools.RuntimeDroolsException: Exception executing predicate org.drools.base.mvel.MVELPredicateExpression Caused by: org.mvel.PropertyAccessException: unable to resolve property: $1" I'm pretty sure I'm not writing the rule correctly in the DRL; does anyone know the correct syntax? The manual isn't clear on this. Thanks!