The tendency for corrective sub-waves within the same wave to take different forms. Most clearly observed between waves 2 and 4 in an impulse, and between the A and B waves in a flat.
Description
Alternation is a guideline stating that corrective waves in the same position tend to alternate in form. In an impulse, waves 2 and 4 alternate: if wave 2 is sharp (e.g., a zigzag), wave 4 tends to be sideways (e.g., a flat or triangle), and vice versa. This principle also applies within corrective patterns such as flats and triangles. Alternation does not say what will happen next, but what will likely NOT repeat.
Key Points
- Waves 2 and 4 in an impulse tend to alternate in form
- Sharp correction (zigzag) ↔ Sideways correction (flat, triangle, combination)
- Alternation in complexity: if wave 2 is simple, wave 4 tends to be complex (and vice versa)
- Alternation in time: if one correction is short, the other tends to be longer
- Also applies within corrective patterns — sub-waves of zigzags and triangles alternate
- Alternation is a tendency (guideline), not an absolute rule
