Critical thinking is "the art of thinking about your thinking while you are thinking in order to make your thinking better: more clear, more accurate, or more defensible."
Paul, Binker, Adamson, and Martin (1989)

Critical thinking is the development of cohesive and logical reasoning patterns. Stahl and Stahl, 1991.

"The purpose of critical thinking is, therefore, to achieve understanding, evaluate view points, and solve problems. Since all three areas involve the asking of questions, we can say that critical thinking is the questioning or inquiry we engage in when we seek to understand, evaluate, or resolve."
Maiorana, Victor P. Critical Thinking Across the Curriculum: Building the Analytical Classroom. 1992.

These three quotes best describe critical thinking as applied to my experience of composing hypertext. These quotes emphasis understanding or the search for understanding of problems. Hypertextual work is in a way disorganized but it follows a strict logic. It sets a sort of structure from which stem new ideas and concepts which further your understanding. The starting page introduces the general idea of the problem and from the multiple hypertextual links littering the page, branches to new ideas of thought extend. You are thinking about your thinking because you are making identifying between different ideas in your work. You evaluate the statements you make and in the end if you are successful, your supporting converge to a solution of the given problem. Success depends on the logical connections between your points. Pages can link to new information, but it must be relevant to the current idea and must eventually converge to the main issue at hand. Essentially, working hypertextually is breaking a big problem into smaller ones and solving them piece by piece in order to complete the whole.