A breakout session is one of several running in parallel after everybody has been in the same room together. The word describes the moment rather than the content: the audience breaks out of the plenary and into smaller rooms. That is why it can mean four different things depending on who wrote the programme, and why it is the least informative word on most schedules.
Where the word comes from
Corporate and academic conference planning, where a day alternates between plenary sessions holding everybody and breakouts splitting them up. In that context the word is precise, because it describes a structural moment in the day rather than a kind of session.
Technical conferences inherited the word without the structure. A single-track regional event has no plenary to break out of, and a multi-track event where every hour is parallel has nothing to break out of either, so the word arrives describing a moment that does not exist.
Why it is the least useful word on a schedule
Because it says nothing about what happens in the room. Reading the chart, the four things it covers ask completely different things of the person walking in: one wants a chair, one wants a laptop and a working environment, one wants a willingness to speak, and one wants the attendee to supply the content.
The word describes the corridor, not the room.
The practical harm falls on the person who guesses wrong. Somebody who came expecting a talk and finds a hands-on workshop without a laptop has lost the hour, and so has somebody who came for a workshop and found forty people watching slides.
What to write instead
The format, in the title or the first line under it. Talk, workshop, discussion, open session. Four words that each answer the question the attendee is actually asking, which is whether they will be listening or working.
Where a programme has to keep the word for structural reasons, the description underneath should carry three things: what will happen, whether anything needs bringing, and how many people the room holds. The last matters more than it sounds, because a session capped at twenty and a session that holds two hundred are different decisions for somebody choosing between two rooms.
Running one well
The failure specific to breakouts is the room. A session split off from a plenary usually inherits whatever rooms the venue has spare, which means a discussion in a raked lecture theatre where nobody can see anybody else, or a workshop in a room with two power sockets.
Matching format to room is the whole job, and it is settled when the venue is booked rather than when the programme is written. That ordering, and what else it decides, is on organising a conference.
How many to run at once
Fewer than the venue allows. The temptation with four spare rooms is to fill all four, which splits an audience of a hundred and twenty into groups of thirty and makes every discussion thinner than it needed to be.
Three parallel sessions is a workable maximum at regional scale, and two is frequently better. The test is whether the smallest of them would still be a good session at the attendance it will actually get, which is a question worth asking before the programme is published rather than afterwards.
What it is confused with
A track. A track is a strand running all day; a breakout is a single parallel session. An event can have breakouts without having tracks.
A workshop. Sometimes the same thing, which is the problem. A workshop is defined by what happens in it; a breakout by when it happens.
An open space session. Part of an unconference, where the subject comes from the room rather than from a programme. See unconference.
The rest is in the glossary, and the format most often mislabelled this way is on brown bag session.
Questions
What is a breakout session?
One of several sessions running in parallel after everybody has been in the same room together. The word describes the moment rather than the content, which is why it can mean a talk, a workshop, a discussion or an unstructured group.
Is a breakout the same as a workshop?
Sometimes, and that is exactly the problem. A workshop is defined by what happens in it and a breakout by when it happens, so one word covers both a session where people watch slides and one where they need a laptop and a working environment.
What should a programme write instead?
The format: talk, workshop, discussion or open session. Each answers the question an attendee is actually asking, which is whether they will be listening or working, and whether they need to bring anything.
Why does the word not fit technical conferences well?
It comes from a day that alternates plenaries with parallel sessions. A single-track event has no plenary to break out of, and an event where every hour is already parallel has nothing to break out of either.
What goes wrong most often when running one?
The room. Breakouts inherit whatever space the venue has spare, which produces discussions in raked lecture theatres where nobody can see anybody else, and workshops in rooms with two power sockets. It is settled when the venue is booked, not when the programme is written.