An online, mass experiment has been launched to try and make the world a happier place. Richard Wiseman, professor of the public understanding of psychology at the university of Hertfordshire is putting "happiness-boosting techniques" to the test via a new website.

On the "Science of Happiness" website participants are asked to take a questionnaire about their mood, and are then shown one of four YouTube videos. These explain a technique that's supposed to improve your happiness which the participant then has to do every day for a week. After a week, there's another quiz to see if it's worked.

Wiseman tells The Times: "I have carried out many mass participation studies, but this is the most important. We are in the midst of a recession and it is vital that people keep their spirits high. This study will help identify the most effective way of putting a smile on someone's face. We need as many people as possible to take part. It doesn't matter whether you are young or old, male or female, or where in the world you live, please participate".

If you're interested in taking part, the quiz can be found at