Although neither side can test directly, the scientific method shown on your link can still be used. For evolution:
1) How did life on the planet become as complex and diverse as it is now?
2) I think that genetic mutation, coupled with natural selection, created changes in populations which, over many hundreds of millions of years, created the diversity of life we see today.
3) I now look for data which is consistant with this theory. I would look for data showing the world to be old enough for all this diversication to occur, for genetic similarities in physiologically similar species, for a fairly ordered and readable fossil record, and I would look for species that seem to display features known only in different groups of animals.
4) Radiometric dating shows the earth to be several billions of years old (consistant with theory), organisms which are physiologically similar tend to have genetic codes much closer to each other than to unrelated species, the geological column has thrown very little in the way of curve balls towards science and it is as neat and orderly as anyone could ever hope for, and lastly several organisms have been found which demonstrate combinations of characteristics now known only to unrelated groups of creatures.
5) Theory looks good given the criteria we have been looking for. Now I should retest my hypothesis and find new avenues from which to attack it.
And now the same for young earth creationism:
1) How did life on the planet become as complex and diverse as it is now?
2) I think that God specially created a limited number of kinds of animals ~6,000 years ago. Some of these were killed off in a massive, world-wide flood some time later but a large portion of these animals survived on a boat that landed in the middle east and then repopulated the earth. Speciation then assisted these surviving creatures in adapting to their new environments.
3) I now look for data which is consistant with this theory. I would look for data which points to the earth being about 6,000 years old and no older, for a mixed up and jumbled fossil record which shows the victims of the flood, I would look for large amounts of genetic variation separating kinds from each other, data pointing to a genetic bottle neck in all animal species that occured in the very recent future, and I would look for fossil remains of unexpected animals radiating out from the middle east (kangaroos, polar bears, giant totoises, etc)
4) I find that civilization began about 6,000 years ago but also find that radiometric dating, ice cores, and dendrochronology all point to the earth being older than 6,000 years, I find a fossil record that is much more organized than I would have expected, I find very little genetic information separating the different kinds of animals, I find no evidence to a genetic bottle neck in all animal species anywhere in the recent past, and I find no fossil evidence demonstrating a mass exodus of non-native animals from the middle east to their current locations.
5) The hypothesis should be rewritten, giving it a much earlier date (about 4.5 billion years ought to do it), remove the part about many species dieing in a world flood, remove the part about all living land animals being the decendants of those that lived on the boat during the flood. Now I should retest my hypothesis and find new avenues from which to attack it.
edited to add a responce