System Evaluation Theory

A Blueprint for Practitioners Evaluating Complex Interventions Operating and Functioning as Systems

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Click here to view a recent blog post about the book from the European Evaluation Association. 

Click here to view a recent Systems Evauation Theory bookchat with ARTD Consultants. 



Outcomes are Not Emergent Properties 

One recurring challenge I encounter when explaining the idea of a system emergent property is that colleagues often want to equate “outcomes” with an emergent system property.  “Well, isn’t the emergent property just an outcome of the complex intervention?” is what I am frequently asked. 

My reply is that I prefer to use the term emergent property when evaluating complex interventions because it does not carry the “baggage” of program evaluation.  Outcomes are often equated with the logic model, as in the immediate, intermediate, and long-term outcomes.  By definition these outcomes are chronological, they are time bound.  This is because the outcomes were derived, using if-then, root cause analysis, reductionist-type thinking.  If you are focused on cause and effect, then by definition one thing precedes the other and there is a time component. 


An emergent property is qualitatively different.  To emerge, according to Merriam-Webster is “to become manifest; to become known”.  What becomes known occurs through the interdependence between complex intervention parts.  Equity, quality of life, stability, and so forth are examples of emergent properties for complex social interventions.  They are not chronological, rather they manifest themselves when the intervention components are operating as they should:  an emergent property is the function of a complex intervention that arises through the product of component interactions (Ackoff, 1994).


I get that there is a certain sense of comfort in trying to equate emergence with something one already knows and is familiar, like outcomes, but they are not the same thing. If you equate emergence with a long term outcome, you miss the opportunity to collect data on the higher purpose of the complex intervention, and the intervention and the evaluation suffers as a result.


- Ralph Renger

Author, System Evaluation Theory: A Blueprint for Practitioners Evaluating Complex Interventions Operating and Functioning as Systems