What vestibular constraint looks like in your classroom.
Now that the domain is defined, here is what its constraint actually looks like in the room you teach in.
Signal 01
Postural seeking behavior
Edging toward the desk edge. Leaning against the wall. Propping on an elbow. Frequent repositioning during sustained seated or floor work. The student is not dysregulated. She is seeking external postural support because her vestibular system is working harder than it should to maintain upright orientation against gravity without it.
Signal 02
Threshold pausing
Pausing at doorways. Hesitating before stepping onto the playground. Standing momentarily still before beginning movement. The vestibular system is loading for a change in spatial orientation. The pause is that processing time made visible. It is not hesitation or avoidance. It is a recalibration in progress.
Signal 03
Simultaneous postural and cognitive demand difficulty
Writing quality that deteriorates during extended writing periods. Comprehension during listening that does not transfer to comprehension during note-taking. The student who can answer questions verbally but cannot produce equivalent written output. Two demanding loads placed simultaneously on a system managing both.
Signal 04
Angular acceleration avoidance
Consistent avoidance of spinning, rolling, swinging, or other activities involving rapid changes in head position during PE or recess. The vestibular system protecting itself from a demand it cannot manage efficiently. Not non-compliance. A system limit expressed as self-protection.
The frequency scale
PSOF uses a frequency-based rating scale, not a severity scale. This distinction is critical. A single dramatic incident, a student falling in the gymnasium, reads as severe. A consistent, low-drama pattern, the same student pausing at every doorway threshold, reads as unremarkable. The PSOF scale inverts this: rate what occurs consistently, not what alarmed you most recently.
When you rate, ask: in the observation window I am rating, how many times did I specifically observe this behavior? Rate that count within the window. Not your general impression of the student. The count.
Observation vs. interpretation
Interpretive
She refuses to sit on the floor.
Calibrated
Student moved to the desk chair during floor sitting on three of five observed mornings.
Interpretive
He zones out every afternoon.
Calibrated
Student's written output declined measurably after 1:00pm compared to morning work samples on four observed days.
Interpretive
She avoids the swings.
Calibrated
Student walked past the swing equipment without engaging on all three observed recesses this week.
The left column contains motivational attributions. The right column contains behavioral data. PSOF certifies the right column.