Handling chatty co workers in a meeting

It's difficult to keep a meeting on track when certain participants seem disengaged and are talking between themselves... difficult especially to resist the temptation just to say "shut up!" and instead affirm your position of leadership firmly but gracefully!
Remember
Avoid the interpretation trap
The participants are talking, doing other things... and we think, "what a lack of politeness and respect!" This interpretation of their behavior works to our disadvantage because it puts us into a stance of judgement and accusation. Of course, lack of attention can be seen as incivility; however, it is also simply the expression of other preoccupations, of the need to "take a breather", and does not target either the group or the leader. This does not mean that it must be accepted but that it does not deserve to be treated as an attack.       
Express your request clearly
What do we want when leading a meeting? The attention and focused participation of each person, to reach the goals and respect the agenda presented at the outset.
This is what must be brought back into view with clarity, precision, and calm. It is a legitimate request.
"You're not listening" or "if you please" are not necessary. It is better to go straight to the point, with a constructive angle and your own personal engagement: "I really need your attention in order to..."       
Ask for a decision
Once the request has been formulated, you can ask the participants to take a position: are they ready to follow you? If so, then they commit to "playing along" according to the rules and a simple look or head movement will suffice to remind them, if necessary, during the meeting. Otherwise, they would rather leave, and will do so without needless friction.       
Evaluation
Each question has only one correct response, but be careful: among the possible responses there is one that is "almost correct" and might make the choice harder!
1 / 3   Separate discussions
Some participants in your meeting have been discussing between themselves for several minutes. What do you do?
You stop taking, while at the same time looking at them.
It will probably be insufficient, or only temporarily effective.
You prefer not to intervene: they are speaking softly and not disturbing the meeting.
Even though they are not disturbing the group, leaving them to talk shows that you are not in control of the meeting.
You address them: "It bothers me that you are discussing between yourselves because the opinion of everybody is going to be important. Can I count on your participation?”
Yes, you express with assertiveness your observation and what you expect.
You ask them "What do you think?".
This is just a one-off move which could be useful but not sufficient.

2 / 3   1st intervention with no effect
Twice now you have asked some participants who are talking to get involved in the meeting. They agree but then continue their discussion. What do you do?
You stare at them to make them understand that it can't go on much longer.
This is probably insufficient.
You calmly say to them: "if I am unable to have your attention, then I would prefer that you leave the meeting".
A diplomatic approach, but you could try one last time to involve them (see response 3)
You calmly say to them:"as I am not able to hold your attention, would you prefer to leave the meeting?”
Yes, this is an assertive intervention and the ball is in their court.
You ask them:" are you not interested in what I am saying?".
Little use in asking this question, they will just say “yes” so as to be left alone.
3 / 3   Capturing their attention?
The meeting agenda is not very captivating and there is a risk the participants will discuss among themselves. In your opinion, which of these 3 introductions is the best?
Our meeting will last 1½ hours. I will do my best to get to the heart of the matter.
Reassuring remark but you could also express your expectation.
I’m going to tackle the 3 topics listed in the agenda, don't hesitate to interrupt me should you have any questions.
You are inviting their dispersion.
I realise that the agenda is not the most attractive for you and I will start by giving you the essential information. Do I have your full attention?
Yes, you anticipate the difficulty and elicit their engagement.
We are going to deal with a difficult subject, I need you to be very attentive and not discuss between yourselves.
It is an anticipated reproach!
Your score is
0/3
You finished!
To review the questions and responses, please choose from the list below.