The pages of the Physics 2000 Website are organized hierarchically by levels of difficulty.

Advantages of HTML hypermedium

• Unlike a book. Nonlinear and unpredictable routes to learning, allowing variations from individual to individual. Linear learners start at beginning, impatient learners in middle, familiarity-motivated learners at end.

• Deeper levels can be more quantitative. Algebra and then calculus.

• Technical caveats and qualifications can be introduced as "dead-ends."