SCHOOLS should develop individual teaching methods that work best for their students, said Mr Wong Sik-wah, Senior Assistant Director of Education, at the Hoi Ping Chamber of Commerce Secondary School's 17th speech day held recently. Mr Wong, who had visited the school earlier this year, commended the institute's efforts to introduce a broader curriculum. ''The aim of the Education Commission's five reports is to improve education. The Government encourages individual schools to achieve this aim by adopting diversified teaching modes,'' said Mr Wong. He said while the Government favoured variety in the schools available in Hong Kong, it hoped to see various teaching methods used within the same type of school. This was to serve the particular needs of students, Mr Wong said. ''For instance, a school should employ a suitable teaching medium, whether Chinese or English, according to the students' language ability. ''It can also provide students with more industrial and practical subjects. Or it can add into the curriculum subjects for the Advanced-supplementary Level (AS-level).'' Mr Wong then drew the audience's attention to one particular group of students. ''It is easy for teachers to attend to students who are both clever and diligent,'' he said. But it is those who have learning difficulties that have a greater need for our concern and encouragement,'' he said. Parents should also try to understand their children's interests and abilities to help them in their choice of education. Mr Wong asked the students to find out where their talents and potential lay through participation in extra-curricular activities. ''Such participation has the benefit of increasing your knowledge and concern about society as well.'' This year is the school's 20th anniversary. In his annual report, Principal Lei Kwok-kit said a whole series of activities had been held to celebrate this milestone. The activities would cumulate in a special anniversary publication to be issued at year-end. ''Since 1973, the number of classes has expanded from nine to 29; students have multiplied from 354 to more than 1,200.'' ''To adapt to the social changes before and after 1997, the school is now devoting itself to developing a generation of educated people who can satisfy the needs of society.'' ''We want our students to be truly bilingual, positive and independent in thinking and analyses.'' ''We would like to see them having a greater concern for their society and possessing a sharpened sensitivity on national and world affairs,'' said Mr Lei.