The intervention leaflets will contain information on the TI's tactics to get young people to smoke.

The control leaflets will contain information on the tobacco control in Hong Kong.

Leaflets for both groups will be printed in colour. Leaflet in each group contains 8 pictures and 8 statement, whose sequences will be scrambled. Primary school students need to do the matching, to ensure they read the statements.

Children will report their opinions towards 4 statements: 1); Tobacco companies are a trustworthy industry; 2) Tobacco industries use many tactics to resist tobacco control regulations; 3) Tobacco industries do everything they can to get young people to smoke; 4) Tobacco industries cheated the public for commercial gain. All the 4 questions have 5 options from definitely yes to definitely no. The options will be recoded into 0-4 or 4-0, as appropriate, with higher scores indicating more negative attitudes towards the industry. A sum of scores from the 4 questions will be deemed as measurement of attitudes towards tobacco industry in primary school students.

Two questions will be used to assess this outcome: 1) If one of your good friends offers you a cigarette, will you smoke it? 2) Do you think you will smoke cigarettes in the next 12 months? Response options are definitely not /probably not /not sure /probably yes /definitely yes. Those choosing options "definitely not" for all the two questions will be deemed having no intention to smoke cigarettes; other responses will be deemed having intention to smoke cigarettes.