I have some questions on the Progress Tests: - How many different Progress Tests are available? - How do I know when I have bought / done all the available ones? - Do the test come in increasing difficulty or are they pre-determined? - Does Duolingo calibrate the test according to your current progress or not? - Can you gain points or lingot by scoring 5? - Do typos penalize you a lot in the final test score, or is it every mistake counts the same?
There is no limit to the amount of progress tests you can take, except for the amount of lingots you have. I believe the difficulty of the test is the same for every one you take. I have never reached a score of 5.00, but I'm fairly certain you don't get lingots for it (maybe XP). Your last question is a bit unclear, but if you type stuff to the extent of it being considered 'wrong', it will count it as wrong.
During the lessons if you make 1 spelling mistake (either in Hebrew / Russian or in English), the result is "almost correct", and you still pass. I am asking if in the final test one gets a lot of penalties for a spelling mistake.
Are the questions for the progress tests picked up randomly from the lesson questions, or are they separate questions?
The progress tests are based on the sentences in the tree. The test is always based on the same pool of sentences, but the difficulty adapts to how well you're doing - get things right, it tests you further down the tree, get things wrong and it tests you on earlier skills.
You don't get lingots, and as far as I've ever noticed, you don't get XP.
There are no limits to how often you can take them except how many lingots you have.
I don't think anyone except Duolingo knows how strict they are as compared to the lessons, or if it's been revealed, I missed it. It doesn't tell you if you got things right or wrong as you go along, so it's hard to estimate. You can guess to some extent by how hard the next sentence is, but it's guesswork.
I do know you don't have to be perfect to get 5/5. I've got full marks in Esperanto, Ukrainian, and twice in Russian, and I am pretty certain I made mistakes in all those tests. (The last time I took the Russian test, even if everything else was perfect (which I'm sure it was not), on at least one question, I accidentally clicked submit before I had finished typing my answer (on the iPad, all too easily done), so I know for sure that sentence would be marked wrong.)