How is the more formal nature of a draft different from the more informal nature of pre-writing?

As students put down their ideas in the pre-writing stage,
they are mainly concerned with the recording of these ideas upon paper before they lose
them.  There is little attention given to the organization of these ideas, the structure
of the sentences, spelling, punctuation,etc.  However, when students prepare for the
execution of a first draft, they organize ideas into a thesis statement, arranging their
subtopics by importance or emphasis. In addition, they select the types of support that
they wish to use with these ideas.

Dependent upon what the
assignment is, of course, is the arrangement and style of students' essays or papers. 
For instance, if a student writes a persuasive essay, there are outlines and standards
to which the essay must adhere.  Or, if a student analyzes a literary work there is
another method used.  For help, see the sites below.