Identification and analysis of stakeholders can be achieved by different methods, and practitioners can rely on well-prepared concepts in this area.  The situation is different when it comes to involving stakeholders. Only few models give an overview of concrete methods and instruments. This means that important basics for planning and decision-making for stakeholder management are missing. This article is intended to fill this gap: It takes up existing categorization approaches and consolidates them in a stakeholder engagement matrix.
As early as 1969, Sherry Arnstein developed the "Ladder of Citizen Participation", in 2004 the International Association for Public Participation published "The Stages of Stakeholder Involvement", and in 2015 the new Stakeholder Engagement Standard was issued by AccountAbility. They all define categories of stakeholder engagement and develop scales that reflect increased participation, sometimes even “Empowerment” and “Citizen Control”, with decision-making power being delegated to stakeholders.
ENGAGEMENT ACCORDING TO DECISION POWER
Accordingly, "Inform" was listed as an essential method of one-way communication. "Consult" and "Involve" stand for two-way communication on different dialogue levels. "Collaborate" and "Empower" already go beyond communication and concern joint action, whereby in the case of "Empower" the decision-making power lies with the stakeholders. All in all, this involves four "two- or multi-way engagements": Consult, Involve, Collaborate and Empower.
Still, all four "two- or multi-way engagement" levels (Consult, Involve, Collaborate and Empower) represent only one dimension of engagement, decision power. But there is another crucial criterion, namely the decision space. It deals with the scope of decision making and the question "What are the stakeholders involved in? What is up for discussion and how self-determined can the stakeholders participate?"
For this reason, AccountAbility's Stakeholder Engagement Standard requires clarification, whether an issue is either operational or strategic before stakeholders are involved. In creativity techniques we find a distinction between "linear" or "discursive" on the one hand and "intuitive" on the other hand. Either existing options are questioned and possibly rearranged often following clear processes (linear, discursive) – so-called "closed" processes - or there is much room for maneuver to introduce (intuitively) one's own new ideas, i.e. "open" processes. The two methods address both, operational and strategic issues, so we also have four categories for decision space .
ENGAGEMENT ACCORDING TO DECISION SPACE
At the lowest level of engagement regarding decision space, stakeholders are asked to provide feedback on specific issues. Additional input can be activated through methods and tools that allow individual input from stakeholders (2nd level). Similarly, stakeholder positions and ideas on strategic issues can be explored using given structures and processes (level 3), or stakeholders can be enabled to fully engage (level 4).
The combination of decision power and decision space creates a matrix with a total of 16 fields that can be grouped into four areas:
STAKEHOLDER ENGAGEMENT MATRIX
A. Reply: Stakeholders are involved in data collection, reviewing existing knowledge or securing planned projects. These include surveys, focus groups or assessments. Both decision power and space of stakeholders are strictly limited. The interaction occurs exclusively through communication and relates to operational issues.
B. Act: Stakeholders participate in the implementation of specific projects. This includes cooperation between companies and NGOs, but also the involvement of stakeholders in the context of traditional project management. Decision-making powers can be delegated to stakeholders involved in negotiations or election procedures, but the room for maneuver is restricted by procedural rules or limited to operative questions.
C. Create: Through open surveys, multi-stakeholder dialogues, open spaces and other formats of large group moderation, the creative potential of stakeholders is used to address strategic issues. However, there is little decision power compared to the great decision space: the interaction takes place exclusively at the level of communication, and the stakeholders rarely have an influence on the actual implementation.
D. Shape: Stakeholders have a high degree of autonomy to jointly decide and implement common concerns. In this category there are many experimental engagement projects such as Future Labs, Citizen Councils or Hackathons as well as new models of self-organization such as Sociocracy or Holacracy.
Whether this matrix actually covers the range of current stakeholder engagement projects needs to be examined further, as well as the distribution of projects across the four quadrants and the precise allocation of existing instruments.
In practice, a negative correlation between decision-making power and space is expected. Hypothesis: "The more decision space available to stakeholders, the lower the decision power assigned, the more decision power they have, the more limited their space."
 Grunig, James E.: Excellence in Public Relations and Communication Management, 1992. Rawlins, Brad L.: Prioritizing Stakeholders for Public Relations, Brighham Young University Institute for Public Relations, 2006; http://www.instituteforpr.org/wp-content/uploads/2006_Stakeholders_1.pdf [05.11.2019]
 Arnstein, Sherry R.: A Ladder of Citizen Participation, JAIP, Vol. 35, No. 4, July 1969, pp. 216-224; http://lithgow-schmidt.dk/sherry-arnstein/ladder-of-citizen-participation.html [05.11.2019]
 “No stakeholder engagement should be initiated without defining a purpose. There are two broad categories of purpose: strategy and operations. That is, stakeholder engagement takes place to develop or improve strategy or to help identify and address operational issues.” AA1000SES (2015), S. 15
 Michalko, M, Thinkertoys: A Handbook of Business Creativity: Handbook of Business Creativity for the 90's, Berkeley 1991