lol, leapforce rater test is the hardest among all. considering i have never seen ISS qualification test, i might be wrong, but I assume ISS is not as hard as leapforce. I have seen LJ and some other members' URHS screenshot and I just think it's easier to separate adult page from non-adult searches and classify news categories. In leapforce they are going to ask you for needs met rating, EAT rating, page quality rating, separate duplicate contents, making sure the info is correct, find out who's behind the website/article, etc. Much more complex. To compare leapforce with appen, I can say appen test is far far easier. Again, i dont know about ISS, but I assume ISS is also easier than leapforce. Good luck, man. Just read the guidelines for hours and you read it again when you are in the middle of the test.