Timing
The timing of when you say something depends on it being relevant to the topic currently being discussed; whether or not you would be interrupting someone else if you spoke; as well as if you have enough time to say everything you need to say.
Making sure what you are about to say is related to the current discussion may seem obvious, but it can be very tempting to fixate on something you want to say, and simply wait for your chance to speak. One of the reasons this happens is that you had something you wanted to say, missed your opportunity to say it, and the conversation has moved on to a new topic.
Let's say you were at a meeting discussing ideas for new marketing strategies and you had a great idea that you were very excited to share. You waited for your time to speak, but it never came, and the conversation moved on to delivery timelines. As the meeting came to a close, in desperation you blurted out, "I think we should email discount codes to customers who have purchased from us in the past, but who haven't purchased anything for the past year." Everyone looks at you, confused, as the time for sharing marketing strategy ideas had passed.
When someone says something unrelated to the topic being discussed, the reaction from other people tends to be, "Where did that come from," or, "Well that came out of left field," or, "I guess they really wanted to get that off their chest."
The situation of having something to say, but not feeling you have an opportunity to say it is extremely common in fast-paced group meetings, where people are speaking very quickly, leaving practically no pauses between when someone has stopped speaking and when another person starts.
This phenomenon tends to be described either as a few people dominating the conversation, not enough people contributing, or both. Whatever the cause, the solution is the same: everyone in the meeting must master the timing of when they can speak so that they are not interrupting anyone else.
Avoiding interrupting someone is where the difficulty arises, because if your timing is only a fraction of a second off you will be speaking over someone, and it is extremely rude to speak over someone while they are speaking.
To pick the right moment to speak in a fast-paced meeting, you must be ready to say what you have to say, which means having an assertive statement already prepared and memorized. You then would have to pay extremely close attention to the people speaking to anticipate when they will be finished, which is no easy feat.
For example, let's say you were in a large meeting having a spirited debate about how to respond to a new competitor entering the market, where everyone was speaking very quickly with practically no pause. You would like to say, "We may want to consider reevaluating our discounting policy," but needed an opportunity to say it. After waiting patiently for the perfect timing, someone finally says, "The way they've structured their pricing makes me wonder if we're still priced competitively," at which point you would immediately say, "We may want to consider reevaluating our discounting policy."
Once you are sure that what you are about to say is on topic, and you are sure that when you speak you would not be interrupting anyone else, you now have to consider if you have the time to say everything you need to say. If you do not, you risk speaking for longer than appropriate, and may be accused of dominating the conversation.
One of the best ways to be an active contributor, but to not dominate the conversation, is to limit the amount of time you are speaking by speaking assertively. However, as assertive communication requires a balance of directness and diplomacy, to limit your time speaking you may have to use less diplomacy, which may not be advisable.
For example, imagine a meeting where many people are discussing the root cause of a serious issue that negatively impacted a large group of customers. In this particular case, it turns out that there was only one person responsible for the issue, which you could quickly communicate as, "Customers were unable to fulfill their orders because Sam unplugged the computer responsible for order processing."
This level of directness would avoid you being accused of dominating the meeting, but Sam would hardly appreciate it. If instead you said, "It's important for us to remember that mistakes happen, and that our main focus should be restoring our customers' faith in our ability to fulfill orders. It's clear now that our order processing computer losing power was the root cause, the solution to which would be to reevaluate the location of our mission-critical computing hardware. In the immediate term, however, we should secure the extension cord powering our servers so that no one else trips on it."
While this version is much longer, there was a need for more diplomacy to help shield your colleague from undue blame.
The more diplomatic we are, the more time we need to say what we need to say, and the higher the chances that we end up dominating the conversation. However, if we don't use enough diplomacy, we run the risk of causing offense and triggering a conflict.
As a general rule, if you ever find yourself needing more time to handle an issue diplomatically than would be appropriate, it may be best to bring the issue up at another time.
Choosing the ideal timing of when to say something requires that we stay on the topic being discussed, avoid interrupting people by choosing the right time to speak, and not speak for longer than is appropriate. While timing can be difficult to master, knowing when to speak and for how long is a required communication skill for being an effective contributor to any group discussion.