The Figure details a method for performing a patents search at the USPTO site.
This is a modification of the method presented at:
http://www.uspto.gov/web/offices/ac/ido/ptdl/step7.htm

and entitled: The 7-Step Strategy

The user may choose to implement the original method detailed there. This is
an example of a for free search which may be performed by the applicant if
he/she so chooses.

The method includes:

a. Reviewing the U.S. Index of classification
Index to the U.S. Patent Classification (Paper, Cassis or USPTO Web).
Alphabetical subject index to the manual of classification. Look for
common terms describing the invention, classes and subclasses numbers.

b. Locate class and subclass with the Manual of Classification
Manual of Classification (Paper, Cassis or USPTO Web).

Locate class and subclass numbers. Scan the entire class schedule,
paying attention to the dot indent. Revise search strategy as needed.

c. Read classification definitions to define relevant classes
Classification Definitions (Microfiche, Cassis or USPTO Web).
Read the definitions to establish the scope of class(es) and subclass(es)
relevant to the search. Use the definitions for future searching.

d. Browse patent titles and abstracts
Browse Patent Titles and Abstract (Classis, WEST - web based Examiner
search tool or USPTO web). Retrieve and browse through titles of patents
and published applications in the given class and subclass. Or redirect the
search: retrieve lists of patents and published applications containing
applicable keywords; note their class and subclass numbers.

e. Retrieve subclass listing
Retrieve Subclass Listing (Cassis, WEST or USPTO Web).
Retrieve a list of the relevant Patent numbers granted and published
applications, for every class and subclass to be searched.

f. Look for examples of applications in the Gazette
Official Gazette - Patent Section (Paper, Microform or USPTO Web).
Look for exemplary claim(s) and representative drawing for all patents on
the list(s) to eliminate patents unrelated to the invention. For published
applications , view the complete document on-line.

g. Review complete patent documents
Complete Patent Document (Microfilm, Paper, Cassis or USPTO Web).
Search the complete text and drawing(s) of closely related patents to
determine how different they are from the invention.

h. Read relevant patents and applications
Read relevant patents and applications. Update list of terms describing
the invention. Update lists of classes and subclasses from cited documents
there.

i. Repeat the above steps as necessary. As the user gains experience
in the field, he/she will better perform all the stages to focus the search
on the relevant issues to the invention subject to the search.