To go with the revamped syllabus, the assessment format for social studies in the O- and N-level exams will be revised from next year.

Instead of structured essay questions, which students typically answer by regurgitating facts, there will be "structured response questions" (SRQ), where students give their opinions or suggestions and make their case.

A Ministry of Education spokesman said: "The new SRQ assesses students' ability to analyse issues from multiple perspectives, construct reasoned arguments and make informed judgments and recommendations."

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Experts said the change means there is "no right or wrong answer", but answers have to be well argued.

SIM Global Education's academic division director Timothy Chan called this a necessary change.

"It shifts the focus from knowledge recall and understanding towards critical thinking and communications... which are skills needed in the 21st century," he said.

The SRQ is worth 15 marks, the equivalent of the structured essay question in the past. The remaining 35 marks will continue to be allocated to the source-based question, where students are asked to interpret and evaluate sources about an issue. The highest possible score for the social studies exam is 50 marks.

For the first time, social studies students will also have to take part in an "issue investigation" project, where they conduct surveys and interpret the data collected. This will be part of their school-based assessment and will not be included in the score in national exams.

Madam Tan Soon May, 42, a social studies teacher who piloted issue investigation at Tanglin Secondary School last year, said it built up students' confidence, even for those who were not so academically inclined.

"It is up to the students to come up with their own conclusions based on the data and evidence they find," she said.

Joanna Seow and Priscilla Goy