response_index
The 1-based ordinal position of this response within the subject's participation in the study. response_index is nested within subjects — not within any lower-level construct (session, activity, block, or trial) — so the counter starts at the subject's first response and increments to their last without ever resetting. Its maximum value for a given subject equals the number of responses recorded from that subject in the study.
info
Part of the Context category of the Response table in the trial schema.
Details
| Property | Value |
|---|---|
| Type | index |
| Requirement | optional |
| Range | 1-based integer, nested within subject (never reset across sessions or activities). |
| Categories | Context |
Notes
- response_index is often redundant with episode_index, but not always: in multitask settings a subject may emit two distinct responses at (approximately) the same time; each response gets its own response_index, but both share one episode_index value.
- In a questionnaire where subjects may answer questions in any order, stimulus_index encodes the order of the questions on the page while response_index encodes the order in which the subject answered them.
- Not to be confused with response_option_index (which option was chosen) or response_id (an identifier unique within this table, assigned in temporal order).