Expert Consultation:
Involves the use of specific talents or experience that either may or may not be present or available within the work group or organization. Implicit within this model is that the correct diagnosis has been made of the problem and that the expertise being purchased will solve the problem.

Examples of expert consultation include marketing, finance, environmental engineering, specific industry knowledge, etc.

Pair of Hands:
This type of consultation is usually contract work that is used to help a client with an unusually heavy workload, project work, or seasonal demands or to meet employee shortages that might be due to vacations.

Doctor-Patient Consultation:
This type of consultation involves the consultant diagnosing the problem and prescribing the solution to the problem(s). The challenges with this model include whether or not the consultant can get an accurate diagnosis on his/her own, and will the client group believe and support the recommendations that the consultant is making.

Involves the leading of a group through establishing an agenda or process to accomplish an objective the group or work team has established. Often facilitators are used to help groups of people who do not know each other well, or may be together for only limited periods of time. Examples include using a facilitator to help a board or a commission to develop a strategic plan, or to design a process to manage a daylong conference of a large group. Usually, facilitators are not experts in content; however, there are times when the term facilitation is used to describe training in certain areas. For example, a facilitator may be used to conduct a workshop on quality when he/she is an expert in quality. In this context, the term facilitation is used more to describe the teaching or training style.

Process Consultation:
This type of consultation can be referred to as ‘small group’ process consultation that involves a focus on group dynamics and behaviors with intent to improve the overall effectiveness of the work group or team. Process consultation does not involve expert knowledge of the content that the group is working with, nor is it involved with establishing the group’s agenda. Process consultation may involve suggestions as to idea generation methods, problem-solving and decision-making processes for a group; as well as dealing with the psychological needs of the group. The psychological needs may include over or under active member participation, controlling or supportive behavior within the group.

Process consultation may also be defined as help with client groups in diagnosing problems, identifying options or solutions, and choosing actions to solve the issues faced by the group or organization. This latter method is similar to action research and classic OD methods and implies a more collaborative approach to consulting.

Active Consultation:
Involves the participation by the consultant in both the content and the process work of the group or work team. Utilizes the experience, expertise, and/or knowledge that the consultant may have to help the team or organization improve its effectiveness. For example, knowledge or experience in finance, planning, experience with small company start-ups, or with corporate culture or politics by a consultant who is using ‘active consultation’ will result in the consultant using that experience and bringing it to the group to add to the perspective of the group to help the group reach better decisions. This ‘content expertise’ is in addition to the consultant’s role and expertise in group dynamics, process, and facilitation.

This is normally the use of active consultation or process consulting roles with individual clients on a one-on-one basis.

Portions of the above are adapted from Edgar Schein and Brendan Reddy