Why your follow-up questionnaire only gets 10% responses
A post-training questionnaire answered by a minority does not measure the training: it measures the motivation of the people who answered. The causes, in order of cost.
A questionnaire sent six weeks after a course commonly gets between 5 and 15% responses. The reflex is to send reminders. That is not where the problem is.
A low rate does not make the measurement imprecise. It makes it wrong.
The common intuition is that a small sample gives a less precise but broadly correct result. That would hold if non-responders were a random draw. They are not.
The people who answer an optional questionnaire two months after a course are, systematically: those who found it useful, those who applied it, and those comfortable with the tooling. Which is to say, precisely the ones whose answers will be best.
At 10% responses you are not measuring the training. You are measuring the 10% it served best.
The result is flattering, stable over time, and useless for deciding anything.
The causes, in order of cost
- Creating an account. By far the largest cause of abandonment. For a five-minute questionnaire, signing up takes longer than the task.
- Installing something. An app required to answer eight questions removes almost the whole group.
- A password issued two months ago. Equivalent to signing up, with the added feeling of having failed.
- A form that does not open properly on a phone. Most answers arrive from a phone, often in transit.
- A subject line that does not say how long it takes. "We value your feedback" gives no estimate of cost; "8 questions, 3 minutes" does.
What works
- A direct link that opens the first question, with no landing page in between.
- No account, nothing to install. Identifying by the address you already have is enough.
- A stated length, and keeping to it. Eight questions announced, eight questions asked.
- Sending at a plausible moment: not Friday at six, not during holidays.
- A reason, in one sentence: what you will do with the answers.
The useful threshold
There is no magic number, but the order of magnitude matters: below 30%, selection bias dominates and the before/after comparison becomes arguable. Above 50%, it is a measurement again.
The main lever for crossing that line is not reminders, it is removing steps. Each friction taken away does more than three follow-up emails. The same reasoning applies in the room: see running a live quiz.
In practice
The SkillLens cold follow-up (paid plans) opens by link, with no account and nothing to install; each participant gets their own, and you see it beside their answers from the session. See also immediate and delayed evaluation.