Anonymity floor

No number shown may identify who answered. The anonymity floor is the minimum number of possible authors a breakdown needs for its numbers to appear.

Possible authors, not responses

The floor is measured against how many people could have answered in that breakdown — the class size or the number of people invited —, never against the number of responses received.

• One response in a class of 30 students is anonymous: any of the 30 could have written it.
• Ten responses in a class of 3 students are not: with so few people, crossing the score with who was in the class reveals who answered.

That is why a breakdown with few responses may appear, and one with many may stay hidden.

What happens below the floor

• The numbers of the breakdown do not appear — and they do not appear as zero, because zero would be a false reading. The screen says the breakdown is below the floor.
• The comments of that breakdown are hidden too.
• The total of the level above remains available.

In a survey answered through an open link, without invitations, there is no way to know how many people could have answered. In that case the floor hides nothing, and the screen says where the decision came from.

When a large breakdown is hidden too

Sometimes a breakdown with many possible authors shows as hidden. It happens when it sits next to a group below the floor: with the total and that breakdown on screen, subtracting one from the other would reveal the small group. A class of 30 students next to a class of 3, for example, is hidden along with it.

• The screen says the breakdown is hidden to protect another group, without showing any number of that group.
• Selecting both groups together, or opening the level above, shows the combined result.

Lowering the floor

The recommended value is 5. Lowering it is a decision about the promise made to respondents, not a display preference.

With the floor at 0 (off), breakdowns with a single possible author are shown — and a comment in that situation identifies who wrote it. A single breach of anonymity is enough to bring down the response rate of the whole survey.

Who sees below the floor

Whoever manages the whole institution already reaches the individual responses through the response list, and is therefore outside the floor by default. The institution can extend the floor to everyone, including these people.