Odd, smart girl.
Montag was walking home from work late at night when he saw Clarisse for the first time. People don't normally walk around at night, but Clarisse did because of he adventurous personality. Clarisse approaches Montag and speaks to him. This is an example of indirect characterization because the author doesn't come out and say Clarisse is adventurous but the reader can infer from the textual content.
Clarisse McClellan is directly characterized as wise in Fahrenheit 451. For example, "Did you know that once billboards were only 20 feet long?" This shows how Clarisse is wise because she knows many facts that other citizens in the community don't know. People in this era are banned from books, therefore they aren't as intelligent as people today. The reason Clarisse is so wise is because she receives her knowledge from the banned books she reads. This is a example of direct characterization because the author gives an example of how Clarisse is wise.