(AP) — It’s tough to come up with the right answer in a job interview, particularly if the question could run afoul of the law.

An Associated Press-CNBC poll found that half of all Americans who’ve ever applied for a job have been asked questions that could be used to discriminate against a protected class under equal opportunity law.

The poll of 1,054 adults was conducted by The Associated Press-NORC Center for Public Affairs Research.

Among those who’ve ever interviewed for a job, 35 percent of the people polled had been asked about their age, and the same percentage had been asked about marital status. Twenty-one percent had been asked about their medical history or whether they have a disability, 11 percent said they had been asked whether they or their partner is pregnant or if they have plans to have children, and 9 percent were asked about their religious beliefs.

Under the laws enforced by the U.S. Equal Employment Opportunity Commission, it is illegal to discriminate against someone — employee or applicant — because of their race, color, religion, national origin, disability or genetic information. It also is illegal to discriminate against anyone because of their age — 40 and older — and sex, which includes gender identity, sexual orientation and pregnancy.

Asking a question related to these characteristics generally isn’t illegal in and of itself. But if the person who was asked the question does not get the job, it could be used as evidence of discrimination. Even if the person hired, the improper question could help build a case down the road of a pattern of discrimination.

For example, a question about marital status isn’t a direct violation but is generally avoided so as to avoid perceived discrimination against parents, or potential parents.

“It’s pretty common to be asked questions that are inappropriate,” said Donna Ballman, an employment lawyer in Fort Lauderdale, Florida. “Usually the bad stuff happens verbally.”

An inappropriate question can signal an effort to discriminate on the employer’s part. But experts say it typically occurs because the interviewer lacks an understanding of, or training in, the law. Interviewers may also accidentally step over the line in an attempt to make conversation, such as asking a candidate who arrives on crutches how they were injured.

Applicants may also offer up information that would highlight sensitive information — such as what language they speak at home or whether they have children — that are off-limits for the interviewer to ask.

While experts say larger employers have instituted more training and made an effort to be aware of these issues, the problems persist on the whole. The experiences were no less common among those who interviewed for a job in the last year than among those who last interviewed more than 10 years ago.

“It’s concerning because when we do discriminate against people it’s typically because of an unconscious bias,” said Kelly Marinelli at consulting firm Solve HR.

Employers should make every effort to stay current on the law — both at the federal and local level — to avoid any issues. Local laws may be more restrictive than federal ones. New York City, for example, prohibits employers from asking applicants about their salary history in an effort to eliminate the gender wage gap. California is considering a similar move.

The rule of thumb for employers is to only ask job-related questions.
Applicants should be aware of their rights. If an applicant is asked a question that is outside the boundary of the law, experts suggest they gently point out that it’s not an appropriate question to answer or steer the conversation back to any job-related or skill-based topics.

“You need to be very professional but firm,” said Dan Ryan of Ryan Search & Consulting.

And if an interview is completely inappropriate it’s fine to end it and leave.

People who feel they have been a victim of discrimination through the hiring process can file a charge with the EEOC or file a lawsuit, typically with the help of an employment attorney.

The AP-CNBC poll was conducted ahead of the premier of the show “The Job Interview,” a new prime-time series on CNBC. The poll conducted Oct. 12-16 by the AP-NORC Center for Public Affairs Research using a sample drawn from NORC’s probability-based AmeriSpeak panel, which is designed to be representative of the U.S. population. The margin of sampling error for all respondents is plus or minus 4.0 percentage points.

Respondents were first selected randomly using address-based sampling methods, and later interviewed online or by phone.