SharePoint 2010 Designer Workflow Action Set Item starting On Item Change Workflow

In SharePoint Designer 2010, I am developing two workflows for a Custom List. One (WF_01) is configured to Start when an item is changed and the second (WF_02) is set to be manually started.

WF_02 updates some fields using the Set Field in Current Item Action. The fields are Choice and Text fields. Whenever a field is set, WF_01 is Started because a field is changed.

It is my understanding that the Set Field action should not cause event receivers to fire, but the Update List Item action does cause event receivers to fire. Is this true? If so, what can开发者_开发百科 be the cause of this behavior?

I don't know what Microsoft's design intent was behind "On Item Change" and whether Set Field was supposed to be treated any differently than Update List Item.

I do know that in my extensive experience writing and maintaining SP2010 workflows, there is no difference in practice. I have learned to assume that any time any column in any List Item is set or updated, that the "On Item Change" workflows are going to fire up and act on that List Item.