2 Historians follow rules to help them analyze

primary sources. Some of the rules they use are:

• Every piece of evidence and every source must

be read or viewed skeptically and critically.

• Each piece of evidence and source must be

cross-checked and compared with related sources

and pieces of evidence.

—Library of Congress

These rules are designed to help historians

determine the

(1) reliability of document information

(2) popularity of a publication

(3) differences in belief systems

(4) laws of a civilization