But Institute of Policy Studies research fellow Leong Chan Hoong said minimum standards may be difficult to determine, pointing out: "Not every Singaporean can speak good English, and what if the new citizen is better off speaking Singlish than English? Would you consider that as an indication of being more adapted or integrated?"

Citizenship tests, some with language requirements, are common in countries with high volumes of immigrants, such as the United States, Britain and Australia.

The one in the US involves a civics test on American history, politics and geography, and an English language test.

"Citizenship tests tell us more about how Singaporeans see themselves than what they expect of new citizens," Dr Chong said.

This is because the tests define the "ideal Singaporean" in the eyes of locals.

Dr Leong said such tests may discourage some from becoming citizens.

But the flip side is that the effort put into preparing for a test may lead to successful applicants who are more inclined to participate fully in society.

He said a test will provide an objective criteria for what a prospective citizen ought to grasp.

Agreeing, Mr Jiang Ler, 40, executive president of the Hua Yuan Association, a group for new immigrants, said: "It gives people a direction to work towards."

But those interviewed were split as to whether the test should be a written one, part of a face-to-face interview, or a combination of the two.

Interviews allow an applicant to be questioned in detail.

Their body language can also be observed, said sociologist Tan Ern Ser.

Mr Tony Du, 53, president of the Tian Fu Club, a networking group for Chinese immigrants, said written tests may not produce accurate results as they allow the book-smart to score well.

For Prof Tan, the attitude a newcomer has towards Singapore is more important than the knowledge he may possess.

"It is also crucial to find out how they have been contributing to Singapore and their attitude in this regard," he said.

"Playing in our team is not the same thing as playing for our team, even if we would like to believe so."

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This article was first published in The Straits Times.