← ERS STAGE 1 · EVIDENCE BOOK34 occasions · 5 raters / 3 complete

Position and randomization

PLAIN ANSWER

The methods did not appear equally often in each screen position, so this pilot cannot tell whether position changed the choices.

To test whether screen position changed a choice, every method must appear fairly across the positions. The build checks that requirement first and stops the position analysis when it fails.

HOW OFTEN EACH METHOD APPEARED IN EACH SCREEN POSITION
POSITION 1POSITION 2POSITION 3POSITION 4A10897B910123C107512D59812
SHOWN EQUALLY ACROSS POSITIONS: FALSE · CAN SEPARATE POSITION FROM CHOICE: FALSE

Screen positions were not balanced. B appeared in position 3 twelve times but in position 4 only three times.

AUDIT DETAILS · V · 34 judgment occasions; each arm shown once per occasion · stage1.position.exposure_imbalance

Stage 1 cannot tell whether screen position changed the choices.

Question content and screen position are mixed together. The position check was added after collection and failed.

AUDIT DETAILS · D · 34 judgment occasions · stage1.position.effect_not_identified

The saved screen assignments fail the position-balance check for the full pilot and for the complete raters.

This check was added after collection and was not planned in advance. Failure blocks a corrected ranking but does not make the saved choices invalid.

AUDIT DETAILS · V · 34 judgment occasions; 16 aggregate arm-position cells; 3 complete raters · stage1.balance.position_gate

The notebook shows one position-adjusted count as a “what if” check. It is not a corrected answer. Some method-and-position combinations were never seen for complete raters, so the data cannot separate screen position from differences between people.

A position-adjusted count is shown only as an exploratory check. It is not a corrected answer.

Some needed method-and-position comparisons were never observed, so the adjustment cannot separate position from rater differences.

AUDIT DETAILS · D · 34 judgment occasions; four observed position-specific rates per arm · stage1.balance.position_standardized