Chapter $2$ lists four factors governing the fair$-$use exemption, which allows you to use copyrighted material without permission under certain conditions. One factor is the nature and purpose of the copyrighted work. What is another factor?

the effect of the use on the potential market for the copyrighted work

the degree of difficulty you might encounter if you did seek permission to use the copyrighted work whether the copyrighted work was published on the Internet, in which case it can be considered to be in the public domain

whether you intended to cause the copyright holder any harm $-$ financial or otherwise $-$ by using the copyrighted material