Partial success needs its own code
Aliases: assisted completion · incomplete success · workaround success
What it is
Partial success is a third code, distinct from unassisted completion and from failure: the person reached a task-relevant result but only with a hint, via an undesigned workaround, or through part of a multi-step flow. Folding it into success inflates unaided reachability; folding it into failure equates “almost there” with “went somewhere else.” Partial success answers a different question—whether the task can be finished with scaffolding—not whether the interface is self-sufficient.
Why it happens
A binary cut discards the middle band of completion quality. One clarifying remark from a moderator, one autofill, or a detour through a support link moves the trace from “arrived independently” to “arrived with outside force.” Those events imply different redesigns: hinted success points to copy or discoverability, workaround success to a missing capability, half-path success to a break in the flow. Without those cells in the codebook, analysis can only raise or lower the success rate, and both moves make one number answer two questions.
Studying it
Keep at least these codes: unassisted success, assisted success, workaround success, partial arrival, failure, and abandonment. Assistance records its source—moderator, system hint, external material—and the step reached before the intervention. Compute the primary success rate from unassisted successes only; report the composition of partial successes separately rather than summing them into “overall usable.” When comparing designs, check whether partial successes were converted from failures or demoted from unassisted successes—the fix differs by direction.
Where it stops holding
Some products treat help centers or human support as a legitimate path; assisted completion is then part of the intended experience and must be declared in the task definition. Assistive technologies used by people with disabilities should not be labeled partial success. In exploration, partial success is a clue, not a figure that must share a confirmatory reporting rule. If almost everyone lands in partial success, the task or product is not yet stable enough for an independent completion rate.
Applying it
- Reserve columns for unassisted success, partial success, and failure on every task sheet; note assistance or workaround under partial.
- Use unassisted success for the headline; keep partial success as a separate line that decides whether to add hints, add capability, or split the flow.
- Do not move “completed after a prompt” into success to make the number look better, and do not dump it all into failure to dramatize the problem.
- In redesign reviews, list the last unassisted step in each partial-success case and aim the fix at that step, not at the total.