Is anybody who wants to travel out of the country will be intervied before he or she can be granted visa? If so, what are the questions he or she will be asked.
Also, what the requirements one need to have before one is qualify  for visa application? 

depends mainly on the purpose of the trip. if its your first time travelling abroad, you will have more questions not to deny you the visa but to screen you and make sure you will comeback home. if its for vacation or family visit, they will want to know about your financial status both at home and abroad, just to make sure you dont go to their country and refuse to return and become an extra burden for them. remember, before you go to the embassy, always get your little details together:finances, contacts,medical etc,

Thank you for replying to my message. I want to travel abroad in order to further my education. What are the necessary information I will will be asked? In order words, what are the necessary information I need to know?

1. Narrow ur intention into a specific region or country.
2. Decide on what kind of degree you intend to pursue ( Bachelor, Masters, Phd)
3. Your age? depending on the degree you intend to study ur age could play a big factor on visa issuance.

Once u lay these information out then you will be able to get specific answers based similiar experience which will do a lot of good to your preparation for an interview.

Thank you for replying to my message, I want to travel to UK in order to have my Master degree in Business Administration. I am 31 years old

Good, Your age is perfect for the degree you intend to purse in the UK.
1. Do a research on schools in the UK
2. Dont approach schools that are known for Nigerians who neglect their courses on arrival or are unable to continue payment of their sch fees, embassies keep datas and they can easily verify sch institution through their data base, which could be basis for denial.
3. Make sure you have good sponsors. If you do, you shouldnt have any problem.
4. Allow your self adequate time to apply for visa before the school season begins at least 2months before the semester. Most embassies deny students base on insufficient preparation time.
4. Prepare for back-up incase you are denied (Not that you will be denied) but its always best to have your plan "B" ready for motion. Your back up should be to "appeal". Most appeals are usually granted if well presented with fact proven documents. I experienced that with my friend back in 2007. In an appeal you really dont need a lawyer, just state your case and prove that your intentions are geniue by squashing what ever doubts the embassy must have had.
5. Pray and fast, make a commitment with GOD. Since we cant really blame embassies for their decision, previous Nigerian visitors who take advantage of the system are responsible for what they do to us. So ur prayers will be necessary to distinguish your self from the rest.

Goodluck.

Thank you all. To attend the interview, what are the dressing codes and the likely questions they normally ask the applicants who decide to travel abroad. Once again, I appreciate your kind gestures towards me.

Tho!, no dressing code is applicable. But like the saying goes if u're in Rome do like the romans. A typical english dressing will be befitting to attend an English embassy. Clean nice packet shirt with slacks to match, this could help create an impression on your personality.

taiwo56:

Is anybody who wants to travel out of the country will be intervied before he or she can be granted visa? If so, what are the questions he or she will be asked.
Also, what the requirements one need to have before one is qualify for visa application?

Some people are interviewed while others aren't. But in ur case, i think you will be interviewed because the visa officer will definitely understand that ur intention is mainly to look for money no matter how and what it takes.
the likely questions that you will be asked are:
1) Can you offload 3 trailers (trucks) loads of cement carrying 2x50kg bags on your head at a time?
2) In the event of lack of jobs, are you willing to work with wheelbarrows in super-markets?
3) Would you also consider farm work which might involve weeding the ground with hoes and digging holes with diggers
As for the requirement for visa, you don't have to worry about that as long as you have faith. so,all you need is a dedicated fasting and praying section, and every other thing will be taking care of by faith. Goodluck