If you’re applying for a nonimmigrant visa to enter the United States – such as a B visitor visa, an F student visa, an H-1B work visa, or some other – you probably realize that the U.S. consulate to which you submit your application has the power to say "No." Regardless of the fact that you qualify for the visa on paper, and have made your plans, been accepted by a school, gotten a job offer, or whatever, the decision is still a subjective one – and it can be influenced by which country you are coming from.
In some cases, the consulate may simply have observed a trend, such as high numbers of people from your country entering the U.S. as tourists or other nonimmigrants and then never returning. In that situation, it might give extra scrutiny to people applying for tourist visas.
In other cases, consular officers may have developed more specific ideas about your country. For example, there’s a story about a consular officer in Eastern Europe who maintained that people from that country would always return home at the expiration of their permitted stay if they owned cows. Later, when applicants got wise and started claiming cow ownership, he began quizzing them on the names of those cows. Applicants who faltered or didn’t supply "cow-type" names were denied the visas.
Although the U.S. government is still working to develop an airtight tracking system for monitoring who leaves the country on time after entering on a nonimmigrant visa, it regularly keeps an eye on the numbers that it does obtain. If, for instance, a high number of people from a certain country are arrested in the U.S., or submit applications to adjust status (get a green card) after entering as tourists, you can bet this information will be relayed back to the consulates that approved the visas.
The U.S. government sometimes also conducts investigations of particular categories of visa applicants. For example, past government reports found high levels of document fraud among Chinese applicants for L-1 visas, and numerous instances of fake employers charging fees to help Indian applicants obtain H-1B visas. The consulates in question no doubt adjusted their practices accordingly.
Talk to friends who have recently obtained U.S. visas, to find out what types of questions they were asked. And if you know anyone who was denied a visa, definitely find out what seemed to have triggered the consular officer’s suspicions or refusal.
You’ll have only a few minutes in which to convince the consular officer that you deserve the visa, so start by preparing your documents carefully, and mentally reviewing the main points that you want to make.
But don’t rehearse a speech. The officer wants to talk to a responsive human being, not a preprogrammed robot. You will be less believable if you appear to have memorized something, and not be in a true dialogue with the visa officer.
If things are going badly -- for example, the officer is acting displeased or obsessively focusing on one area of your application -- speak up and explain what the officer has overlooked. If the issue is whether you’ll return home after your stay, you might also ask the officer what further evidence he or she will accept. Two possibilities include a nonrefundable airplane ticket or a "maintenance bond" (a sum of money that you submit to the U.S. government that you forfeited if you do not leave the U.S. when you say that you will).