Quality of content

More important than the amount of time you speak for, is the quality of what you have said and the impact that it has had on the group. You do not have to dominate the GD by speaking for a long period of time. You have to influence a group by providing it direction, by highlighting the crucial issues and putting forth persuasive and cogent arguments. There is no formula to calculate the right duration of participation in a GD. In a 15-minute GD in which there are 12 participants, if you are able to speak for two minutes spread across four or five occasions, it should be enough.