The IP Counsel Blog discusses
whether provisional patent applications should include claims:
In Claims in Provisionals, Russ [Krajec] advocates that provisional patent applications should be filed without claims. Russ' reasoning is that provisional applications filed with claims can only have a negative effect in view of prosecution history estoppel. . . .
I feel that it is prudent to include the broadest claims in the original application. If the validity of the patent is ever attacked, there is a record of the broadest claim in the application with the earliest filing date or priority date. At the risk of establishing a record for prosecution history estoppel, it is necessary to preserve a record for claim interpretation and to satisfy written description requirements.
Check out the rest.