An outcomes hierarchy
An outcomes hierarchy [1] in outcomes theory describes knowledge claims about a particular set of causes and effects in the real world; as such they should be viewed as someone's claim regarding the set of causes required to ensure that the highest-level outcomes in the hierarchy are achieved. Outcomes hierarchies are often drawn before the outcomes in question are achieved, but they can also be drawn after the fact. When drawn after the fact they are a claim, not about what it is believed will happen, but about what has happened. In either case parts, or all, of a particular outcomes hierarchy may or may not correspond to what actually happened in reality.
In outcomes theory, the elements within an outcomes hierarchy are generically referred to as "outcomes" no matter what causal level they are at (i.e. for the purposes of outcomes theory "outcomes" can include causes which are at a low level and which are referred to in some outcomes systems as activities or outputs and are sometimes claimed to be mutually exclusive of "true" outcomes in such systems).
Within outcomes theory, for something to be allowed to be an element within an outcomes hierarchy it needs to meet the following formal requirements:
1. It has to be either a cause of on or more elements in the outcomes hierarchy or be caused by one or more other elements in the hierarchy, or be both the cause of one or more other elements and be caused by one or more other elements in the hierarchy.
2. It must also be one of the following:
• a low level outcome which is fully controllable by an intervention organization and is undertaken in order to influence higher-level outcomes (a group of such low level outcomes are known as an intervention in outcomes theory);
• a higher-level outcome which is being deliberately sought by a control organization and/or an intervention organization;
• a mid-level outcome which is one step on the causal chain from low level to high-level outcomes;
• a higher-level outcome which is also caused by outcomes at lower levels but which is not an outcome being deliberately sought by a control organization and/or an intervention organization (these are often called unintended consequences).
It should be noted that there is no presumption in this definition as to the number of levels allowable in any particular outcomes hierarchy. The number of levels in any outcomes hierarchy should be determined by the number of causes in the real world which need to be explicated in order to give the outcomes hierarchy sufficient analytical power for its users. This means that in some cases it might just have two levels (intervention - higher-level outcomes) and in other cases their might be a great number of levels between the intervention and higher-level outcomes. If users wish, they can also take outcomes hierarchies down below the level of interventions and specify the cascading sets of causes which are required in order to achieve the "outcomes" which go to make up an intervention.
There is no formal requirement that outcomes hierarchies be "visualized" in the way that they often are (e.g. as two dimensional diagrams on paper), because they can be adequately described as a set of relationships between elements set out in mathematical or formal logic notation. However, because outcomes hierarchies are often visualized to allow non-mathematicians to work with them and for rapid communication with stakeholders, one can talk in a metaphorically shorthand way about "drawing outcomes hierarchies".
In such drawings within outcomes theory, prior causes are usually drawn at the bottom of the diagram with the sequence of causes running upwards to the highest level outcomes at the top of the diagram. What is accepted as constituting evidence for a "causal link" within an outcomes hierarchy depends entirely on those who are drawing the outcomes hierarchy. There can be two bases for claiming such causal links: 1) empirical evidence from previous research; and 2) straight analytical reasoning in the absence of decisive empirical evidence. In outcomes theory there is no requirement that only outcomes for which there is empirical evidence are included in outcomes hierarchies. Outcomes hierarchies are a subset of the wider category of what are called intervention logics, program theories, or theories of action.
An outcomes hierarchy is formally defined as – a set of claims about a hierarchical set of causal linkages.
Outcomes hierarchy types
A number of different types of outcomes hierarchies can be drawn which contain different types of knowledge claims about the causal links between outcomes. Causal links within outcomes hierarchies can be either hypothesised or established. Causal links within an outcomes hierarchy are established when they meet the criteria for establishing a causal link of a community of users of that outcomes hierarchy. In some cases these are made explicit by the community of users (for instance, in evidence based research colation programs such as the Cochrane Collaboration [2]. In other cases they are not made explicit. The criteria for establishing a causal link can be based on either empirical evidence or analysis.
An hypothesised causal link within an outcomes hierarchy is formally defined as - a claim about a causal link between outcomes within an outcomes hierarchy which has not met the acceptable criteria for establishing a causal link of a community of users of that outcomes hierarchy.
An established causal link within an outcomes hierarchy is formally defined as - a claim about a causal link between outcomes within an outcomes hierarchy which has met the the accpetable criterial for establishing a causal link of a community of users of that outcomes hierarchy.
A community of users of an outcomes hierarchy is formally defined as - is a group of people who are implicity or explicity in agreement regarding the criteria for establishing a causal link within an outcomes hierarchy. There may be more than one community of users for any one outcomes hierarchy.
A set of criteria for establishing a causal link within an outcomes hierarchy is formally defined as - a set of rules agreed to by a community of users as to which claimed causal links within a particular outcomes hierarchy are accepted as providing sufficient grounds for deciding on future action, in a way similar to the causal connection having actually been established as being true in reality.
The use of empirical evidence within the criteria for establishing a causal link is formally defined as - the acceptance of the use of information which a community of users regards as being in some way based on more than just analytical reasoning due to its grounding in some way in observations of the world.
The use of analysis within the criteria for establishing a causal link is formally defined as - the use of information which a community of users regards as being in some way sufficiently disciplined so as to be based on more than just opinion or not-fully analysed hypothesis.
Notes:
[1] There are a number of other terms which are used in outcomes systems which are related to, but which may differ in significant ways from, outcomes hierarchies. These terms include: intervention logics, programme logics, programme theories, theories of action, causal maps, results chains, strategy maps.
[2] The Cochrane Collaboration is an international collaboration of health and medical researchers who provide systematic and continually updated summaries of the findings of controlled trials in a wide range of health areas. See www.cochrane.org. A similar collaboration has been set up in the social sciences - the Campbell Collaboration, see www.campbellcollaboration.org.
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