The floor nobody declares

Here is a question almost no rubric answers, and every student eventually asks: what do I get for doing nothing?

On the most widely used rubric scale in the world, the answer is 25%.

Where the quarter comes from

The classic scale is 4 · 3 · 2 · 1 — Exemplary, Proficient, Developing, Beginning. Mark the bottom level on every criterion and the arithmetic runs:

$\frac{\sum w_i \cdot 1}{\sum w_i \cdot 4} = \frac{1}{4} = 25\%$

The lowest level is worth a quarter of the highest, so the floor of the scale is a quarter of the grade, handed out before any work is read. Nobody wrote that policy. It arrived attached to the numbers.

And the ceiling has a matching surprise. Mark Proficient on everything — the level whose name says the student did what was asked — and the score is 3 ÷ 4 = 75%. A C.

Read that table as a set of claims about your students, because that's what it is. It says competent work is a C, and it says partial credit starts at a quarter. If you'd defend both, keep the scale. Most people, seeing it written out, would not.

Only 75 of the 100 points exist

The floor doesn't just inflate the bottom — it compresses the whole instrument. With a 25% floor you have 75 points of range to express every distinction you care about. Every scale makes this trade:

• 4 · 3 · 2 · 0 — the same four levels, bottom worth nothing. Full 0–100 range, and "not evident" finally scores what it says.
• 100 · 85 · 70 · 55 — levels mapped straight onto letter bands. Gives away the most (55) and buys the thing the classic scale gets wrong: proficient lands on a B.
• 3 · 2 · 1 — faster to mark, coarser to appeal, floor at 33%.

There's no correct answer here. There's a declared answer and an inherited one.

Two honest ways out

Change the mapping. If proficient should be a B, use a scale where it is. This is the direct fix and it takes one dropdown.

Or keep the scale and change what you do with the number. Plenty of departments use 4·3·2·1 deliberately and never convert it to a percent — the rubric reports a level profile, and the course grade is set by a separate policy. That's coherent too. What isn't coherent is running 4·3·2·1 straight into a percentage gradebook and being surprised that solid work keeps landing on C.

The tool won't pick for you. It will tell you, every time, what your current scale's floor is and how much range you have left — which is the only part that was ever hidden.

Run it

Open the rubric builder on the classic scale:

1. Read the "what this scale can express" panel: 100 / 75 / 50 / 25, with the letters beside them.
2. Switch to 4 · 3 · 2 · 0. The floor message flips — the full range is reachable — and the bottom row finally reads 0%.
3. Switch to 100 · 85 · 70 · 55 and watch proficient move from C to B without any student doing anything differently. That's how much of a grade lives in the scale rather than in the work.