If you’re a tester and you’ve been around social media, attended a conference, watched a webinar, read blog posts, or watched videos of other testers speaking on YouTube, you may have heard at least one mention of polimorphic and/or mimeomorphic actions. But what does it mean when someone says that an action is polimorphic or mimeomorphic? Where do these ideas come from, and why, as testers, do we care?

The concepts of polimorphic and mimeomorphic actions come from the book The Shape of Actions: What Humans and Machines Can Do, by Harry Collins and Martin Kusch. In the book the authors develop a new theory about what they call the shape of actions. I’ve attempted to cover the highlights and general topics of discussion, or at least what I found most interesting, from each chapter in the summary below.

Chapter 1 – Humans and Machines

In Chapter 1, Collins and Kusch introduce the reader to their theory which basically states that humans can do three things – they can do polimorphic actions (actions that draw on an understanding derived from a sociological structure), they can do mimeomorphic actions (actions that are performed like machines, and do not require an understanding derived from sociological structure), and they can merely behave. The authors are concerned with how actions look from the point of view of an observer; they say they are concerned with the “shape” of actions, or what they call action morphicity. The authors conclude their introduction to the shape of actions by discussing the two key entities of this theory – the humans, which are all entities that can perform polimorphic actions, and the machines, which are all entities that cannot do polimorphic actions, and how the boundaries between these two entities is permeable (after all, humans do act like machines in many instances), and how the theory of actions may establish new boundaries between humans and machines.

Chapter 2 – Methods and Principles

This chapter begins the discussion of what a theory of action is by suggesting that actions may be classified as one of two types, depending on the behavior that instantiates them. The authors also make the distinction between actions (the things that we can do in a society, that get their sense from taking place in that society) and behaviors (physical movements, including those that we use to execute the actions we intend), with the primary differentiator being that actions are intentional. In particular, the theory of actions is concerned with what are called formative actions, those actions which not only get their sense from taking place in a society, but that also make that society what it is and distinguish it from other societies. The authors then go on to describe how actions and institutions are what they term “social kinds” because they exist only as long as those who are in the society/institution act as though they exist (for example, money), and “natural kinds,” which continue to exist regardless of how those taking part in the society choose to act.

Chapter 3 – Morphicity: What the Action Is

Chapter 3 examines the classification of polimorphic and mimeomorphic actions before introducing a means of representing actions as diagrams. In the case of polimorphic actions, the authors take advantage of the fact that polimorphic actions typically use different behaviors to carry out the same action in different contexts, and identify three subtypes of polimorphic actions based on context and behavioral response:

  • Open Polimorphic actions are polimorphic actions in which both context and response are open (for example, love letter writing)
  • Occasioned Polimorphic are polimorphic actions in which the context is open but the response is not (for example, voting)
  • Playful polimorphic actions are polimorphic actions in which the context is closed but the response is open (for example, relieving tedium or expressing individuality)

Mimeomorphic actions, on the other hand, lack the association with context that is a characteristic of polimorphic actions, and are classified by preference as too how they are carried out (either casual, in which case the action is marked by our indifference to how the action is accomplished within limits – the envelope of acceptable behavior, or special, in which case the action is marked by our preference for the same behavioral instantiation each time) and plurality (either singular, in which there is only a single way in which the action may be performed, or disjunctive, in which the actor must choose from one of a set of acceptable ways in which to execute the action). This allows the authors to identify four subtypes of mimeomorphic actions:

  • Special Singular Mimeomorphic actions are actions in which the action should be performed the same way each time and a single way in which it should be performed (for example, swinging a golf club)
  • Special Disjunctive Mimeomorphic actions are actions in which the action should be performed the same way each time and the actor must choose from a set of acceptable ways to execute the action (for example, expert golf club swinging)
  • Casual Singular Mimeomorphic actions are actions in which there is an indifference in how the actions should be carried out (so long as it is within an acceptable limit) and a single way in which it should be performed (for example,  telephoning one’s mother from home)
  • Casual Disjunctive Mimeomorphic actions are actions in which there is an indifference in how the actions should be carried out (so long as it is within an acceptable limit) and the actor must choose from a set of acceptable ways to execute the action (for example, telephoning)

Chapter 3 also introduces what the authors call an action tree. Action trees are diagrams that represent the relationships between actions, and look much like decision trees with the exception that the authors adopt some conventions to indicate the morphicity of the action represented at a certain node. In an action tree, the nodes at the higher levels represent actions that are realized further down the tree by other actions that are more specifically defined.

Chapter 4 – A Theory of Interaction

The authors begin discussing interactions, both within a culture (humans to humans) and across cultures (humans to machines) in Chapter 4. The primary means of intra-cultural interactions is via action cascades, in which one actor, A, carries out an action for another actor, B, in such a way that A’s action is a sub-action of B’s action. The polimorphic/mimeomorphic dichotomy is applied to action cascades at the point where the transfer of action takes place, resulting in the identification of two types of cascades – Control Cascades, in which the action above the transfer is polimorphic and below the point of transfer is mimeomorphic, and Indifference Cascades, in which the action above the transfer is mimeomorphic and below the point of transfer is polimorphic. Since polimorphic actions derive understanding from within our sociological structure, and that structure is non-existent across cultures, the authors conclude that different cultures may only incorporate the mimeomorphic actions of other cultures into their own action cascades.

Chapter 5 – Morphicity and Human Competence

Chapter 5 begins the discussion on what is involved in human learning, and how the theory of actions applies to human competence and the transfer of sets of actions. The authors guide the reader through several examples of actions, starting with special singular mimeomorphic actions which are learned through “calculation”  that requires no need for practice or drill, through increasingly complex actions, ending with polimorphic actions that can only be learned through social skills. The authors provide two main insights through these examples. First, they show how action morphicity helps us understand how competencies are learned. Second, they demonstrate that the mimeomorphic/polimorphic dichotomy does not correspond to other ways of dividing up our abilities. For example, mimeomorphic actions may be either skilled or unskilled and they may be self-conscious or internalized. The chapter concludes with a discussion about the ability to transfer sets of actions or competencies between cultures, establishing the “irreplaceability thesis” which draws on the self-referential nature of polimorphic actions to state that they may only be learned by social interaction within the society to which they belong, whereas mimeomorphic actions can be decontextualized, and hence may be transferred between cultures.

Chapter 6 – Writing

In Chapter 6 the authors examine several different forms of writing within the context of the shape of actions to assess if the action of writing is polimorphic or mimeomorphic. Not only do different styles of writing (say script writing or calligraphy) have different morphicities, but the morphicities also differ within the same style of writing. For example, a child’s script (as they are learning) is a special other-copying singular mimeomorphic action whereas the adult’s script can be seen as casual disjunctive self-copying mimeomorphic action. Interestingly, the adult’s script can also be seen as a casual singular self-copying mimeomorphic action when using the individual as context and as casual disjunctive self-copying mimeomorphic action with respect to other individuals. This apparent duality lends much credence to the author’s caution that “one must look at each action in considerable detail, for actions are not always what they seem to the casual glance.”

Chapter 7 – Machine Behavior and Human Action

Chapter 7 covers a lot of ground on the complex task of mapping machine behavior to human action. It begins by discussing how machines are classified, saying that either we can classify them by what they do or by how they work. The authors then discuss three types of machines based on what they do:

  • Tools, which help us to improve on what we already do (a hammer)
  • Proxies, which are used to replace us by doing the things we already do (some computer programs)
  • Novelties, which allow us to do things that we could not do without them (a freezer)

The authors make an interesting observation that proves to be fundamental in determining what machines can do: the differences between the three types of machines are largely a matter of perspective based on where we are in the action tree. This leads to the general rule that we can view tools as proxies by using a vantage point lower in the action tree, and we can view proxies as tools by taking a higher vantage point in the action tree. The argument then follows that what we have been seeing as proxies should really be seen as tools because we have been inattentively “repairing” the deficiencies of the machines and attributing the machine with doing an action for us when it was really only helping us to do the action better. The authors then bring the power of a fully operational theory of actions into play by saying that machines can only act as proxies when the actions they perform are far enough down the tree as to be mimeomorphic, and that the proper attribution of agency can only be applied up to the point in the action tree where polimorphic actions begins.

Chapter 8 – Organizations and Machines

Chapter 8 applies the dichotomy to organizations, and seems to extend the findings from the previous chapter by saying that even with respect to organizations, we have had the wrong vantage point, and so even the things we thought were mimeomorphic are instead polimorphic. The rules within bureaucracies, for example, do not come with rules for their application, and thus still require contextual interpretation by the actor. The book also gives the example of “complete deskilling” at a restaurant such as McDonald’s where replacing esoteric with ubiquitous skills makes it seem like a mechanical process, but it is not deskilling because it is a transference of the responsibility of exercising the skills to another actor (the customer in the case of McDonald’s). The authors discuss how the dichotomy may be applied to the world of science, showing that what is typically presented as a field dominated by mimeomorphic actions is, in fact, heavily reliant on polimorphic actions, and has been made to appear so due to the repair that historians have made as they recorded the events.

Chapter 9 – The Automation of Air Pumps

In Chapter 9 vacuum pumps are used to examine the skills required to operate a device, and how those skills change as the device changes. Comparing the use of modern, automated vacuum pumps and Robert Boyle’s experiences with vacuum pumps in the seventeenth century, the authors found that skills don’t change much when we have active closure because those skills are still needed to operate the device, but they do change as we move towards passive closure. In the case of active closure, which says that an instrument whose use has been accepted and whose general principles of design have been settled still requires skill and agreement to make it work, we have theoretical indifference at this point (say that we are indifferent to what mixture is used to seal the leather used in Boyle’s pump) but not behavioral indifference. Skills do change once we begin moving towards passive closure, however, because we have moved into the realm of behavioral indifference, and at a certain level it becomes a matter of indifference to all parties, at which point we are talking about mimeomorphic actions.

Chapter 10 – Conclusion: Dichotomies and History

The authors begin the discussion in the final chapter of the book by pointing out that the distinction between polimorphic and mimeomorphic actions does not match other dichotomies, such as the action versus behavior dichotomy, the action versus basic action, and several others. The point the authors make between their theory and other theories of action is their theory states that, in principle, all mimeomorphic actions may be mechanized, though some of them may be too complicated to do so, because the way the engineering is done is not crucial in the theory they provide. Instead, they claim that the idea of mimeomorphic actions creates a common ground for actions and behaviors that other theories do not.


The Shape of Actions is a tough yet rewarding read. It’s rather academic, and is one of those books written for another field (the authors refer to it as sociphilosophy), but it remains very applicable to software testing, and is a book that I’ll be returning to frequently.

My thoughts kept turning towards test automation as I read the book, which really makes sense given that the theory creates a common ground where actions and behaviors can cohabitate and discusses, in great detail, what machines and humans can do. In particular, I found the discussions on special and casual disjunctive mimeomorphic actions very beneficial with respect to model-based test automation. But there are many more ways that the information from the book may be applied to testing software, whether it’s during test planning, test design, test execution, or test reporting. I plan to post several follow-up posts based on ideas from the book and how I apply those to my testing activities.

My challenge to you is to read the book, apply what you learn from it to improve or expand your own testing activities, then come back here and post a comment to let me know how you have put that information to use.


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