It occurs to me that committees have a bad reputation. They move slowly. They are prone to circular decision-making. They often require a lot of energy for very little result.
Task forces on the other hand are thought of as more efficient. They move quickly. They operate more like 'special ops' than a full army.
So what is the difference? Why would one group of people--with an intent to collaborate--function so differently than the other? I believe the key difference is in the construct and expectations.
Committees are often collections of people representing different interests. For example, a university facilities committee might have people from various departments, student representatives, administrative members... Each person participates based on a mission to represent their group.
A task force--however--is made up of people selected for their individual skills as it relates to an objective. For example, a site search task force might include a commercial realtor, an assessor, a marketer, someone with administrative talent, a person with deep understanding of the user group... Each person is there to complete the objective.
Committees are assembled for the long term with different members rotating in and out. Issues can be debated and decisions made with no real impact on the individual members. In fact, many times as the make-up of the committee changes, it can be difficult to trace back why certain decisions were made in the first place. Success would be measured differently by the groups represented based on how well their agenda was met. In fact, this idea of "different agendas" may be the single reason committees so often produce mediocre results.
Task forces are mission-specific. Success is measured based on the objective rather than by individuals in the group. Moreover, when the objective is complete, the task force dissolves and new task forces are assembled to complete different objectives.
So, the next time you are asked to serve on a committee, you may want to pass. Being invited to a task force would be much more satisfying.