Instant feedback vs a quiz at the end
Being told at once stops you practising a mistake. A score at the end is for measuring. Why lessons check each answer on Enter and the skills test waits.
Instant feedback tells you a formula is wrong while you still remember why you typed it. A quiz at the end tells you later, after you have moved on. When you are learning to write formulas, being told at once works better. When you want to know your level, the end is the right time.
What a score at the end does
You answer ten questions. Then you see 6 out of 10. Now you have to find the four wrong answers, and remember what you were thinking for each one. Often you cannot.
There is a worse problem. If you misunderstood something in question two, you may repeat it in questions three to ten. You practised the mistake eight times before anybody told you.
What instant feedback does
Each answer is checked when you press Enter. If it is wrong, you fix it on the same sheet, a few seconds later. The next question starts from the right idea, not the wrong one.
Research agrees, with one limit. A review of many studies by Kulik and Kulik (1988) found immediate feedback worked better in real classes. In some laboratory tests a short delay helped memory. But writing formulas is a skill you use again and again. For a skill like that, being told at once stops you practising a mistake.
"Wrong" is not enough
Fast feedback helps only if it says what went wrong. A red cross after
=SUMM(B2:B6) teaches nothing. This does:
This sheet has no function called SUMM. Did you mean SUM?
The same is true for the other common mistakes. Type the answer as a number, and you read that you typed the number, not a formula. Forget the =, and you read that a formula starts with an equals sign. How your formula is checked lists each check and its sentence.
When the end is the right time
A test that tells you after every answer is teaching you during the test. That is good in a lesson. It is bad when the aim is to find out what you can already do.
So this site does both. In the lessons, every step gives instant feedback. In the skills test, you see how you did at the end, not task by task. The lessons teach. The test measures.
Instant feedback in Excel itself
Excel can show you what part of a formula does, too. On Windows:
- Evaluate Formula. On the Formulas tab, click Evaluate Formula. It works through the formula one part at a time and shows each result.
- F9 on a piece of a formula. In the formula bar, select part of the formula and press F9. Excel shows its value. Press Esc afterwards, or the value replaces that part.
Both tell you what a formula does. Neither tells you what it should do. That is the part a lesson with a known answer can add.