Not all spoken text should be on your sheet, as your performance should not be a recital of your sheets. But spectators should be able to fully follow your scientific line of arguments without having to listen to you.

Allotted time

Never say: “If time will allow …”. You know how much time is left, and you know precisely when you have to stop.

Independent of the context of your presentation, stick to your allotted time. Or, even preferably, end somewhat earlier. Never ask the chairman in public, when you start, how much time you have gotten. Or during your talk, how much time there is still left. Such questions prove your poor preparation.

Defend your time

You should even override the chairman if he is, in order to catch up with a delayed schedule, stealing a part of your time. Observe the exact time when you start. If you see that the chairman becomes nervous way before your time has lapsed, say to the audience, looking conspicuously at your own timing device, “In the remaining x minutes I will …”. And you should know x precisely. A large count-down timer owned by you – and not by the chairman – is very convenient. A large digital kitchen timer will do.

Volume, tone and pace

Do not let your voice betray you. If you have not rehearsed your talk well, you are sure going to show your insecurity with respect to certain parts of the content by unwanted hesitation, unwanted stammering, and undesired reduction of the volume of your voice. Or you will get trapped into a never-ending sentence. Especially when you explain shaky arguments, behave like an actor and present that part of your work as rock solid science.

Volume

You can hardly speak too loud. Many speakers (25%) speak with a voice that is too soft. Remember that all non-native speakers (maybe including yourself) have strong accents. The audience has to get used to your funny accent.

Pace

Your speed of talking can hardly be too slow. Many speakers (25%) go to fast.

In some countries normal speech is fast (for instance in France and Spain). Like all non-native speakers, these rapid speakers will have a strong accent. If you belong to this category, be very careful. If you do not slow down continuously, your whole talk will be wasted.