This is such a copout to me. Do me a favor Google something as simple as minimum tank size for an Oscar. See what you come up with. Sure there is tons of info available from Google but if you don't already know the answer how do you know who to believe? Isn't that the point of forums? To collect info from a large group of people with similar interests?
Talking about building a basis of knowledge to understand the answers your getting. Gotta know what an oscar is, right? Alot more info is needed to keep an oscar then just minimum tank size. Within 5 minutes you can google this info and verify it on a dozen sites taking another 10 minutes. Now that you have an understanding of the size they get and the filtration needs, you can now easily understand what size tank they need if that was missed in the research, or too much conflicting data on minimum tank size is found.
If this is the case the doubt it's a "basic" question anyhow.