(Powell et al., 2024)
Source: (DOI: 10.1177/13563890231196601)
-
History / lineage (why this isn’t “new”, just under-used in evaluation): Causal mapping (diagramming “what causes what” using directed links between factors) has been used since the 1970s across disciplines (e.g. Axelrod-style document coding of causal assertions; management/OR traditions emphasising maps for decision support; comparative methods like Laukkanen’s work on standardising factor vocabularies and combining maps). The evaluation literature has relatively sparse, inconsistent “causal mapping” usage; this paper synthesises the wider literature and re-specifies it for evaluators.
-
How we pitch it to evaluators (the niche): treat causal mapping as a discrete evaluation task: (i) systematically assemble causal evidence from narrative sources into an explicit link database with provenance, then (ii) separately use that assembled evidence to make evaluative judgements about “what is really happening”. This is positioned as a way to work with large bodies of messy, heterogeneous qualitative causal data (different boundaries, contexts, specificity, and ambiguity) without forcing early convergence on a single prior ToC.
-
How causal mapping differs from adjacent approaches:
- Primary object is evidence-with-provenance: causal mapping is explicitly about who/what source said what link, not a modeller’s best estimate of system structure.
- Epistemic first, ontic later: unlike approaches mainly aimed at simulation/prediction (e.g. SD/BBNs/CLDs/FCMs as typically used), causal mapping foregrounds organising claims/evidence; inference about reality is a later step.
-
Lightweight causal typing: it usually does not require consistent weights/functional forms/necessity-sufficiency labels; it can incorporate them when elicited, but warns about spurious precision.
-
How causal-mapping approaches differ among themselves (key axes):
- Mode of construction: coding documents vs coding interviews vs group map-building (consensus/problem-structuring) vs hybrids.
- Elicitation openness: closed (pre-specified factor lists) vs open (respondent-generated factors), with chaining variants (forward/back).
- Single-source vs multi-source & context handling: idiographic maps vs aggregated multi-source maps; whether and how you track case/context metadata to avoid invalid transitive inferences.
-
Coding philosophy: “factors as variables” vs “factors as changes” (e.g. QuIP-style); whether polarity/opposites are represented as separate factors/links or handled differently; extent of factor-name standardisation/merging/nesting.
-
Problem / motivation: Evaluators need to represent (a) what causally influences what in the world, and (b) what different stakeholders claim/believe causally influences what. Causal mapping—defined as the collection, coding, and visualisation of interconnected causal claims with explicit provenance—is widely used outside evaluation, but under-specified in evaluation practice/literature.
-
Core argument (the “Janus” dilemma + resolution):
- Janus dilemma: Causal mapping faces two directions—maps can be read as models of beliefs or as models of causal reality; in practice these get blurred unless source information and analysis steps are explicit.
-
Resolution: Treat causal maps primarily as repositories of causal evidence (epistemic objects), not as direct models of either beliefs or reality. Maps then support structured questions like: Is there evidence X influences Z? Directly/indirectly? How much evidence? How many sources? How reliable? The evaluation step that judges “what is really happening” is distinct and subsequent.
-
What causal maps encode (and don’t):
- Epistemic content: Map elements are claims/perceptions/evidence, not facts.
- Causal semantics are usually coarse: ordinary language claims typically encode partial influences, not total/necessary/sufficient causation; coding a link need not assert evidence quality (though you may later weight/filter by quality).
- Multiple sources + contexts: maps may be single-source or multi-source; inference across sources requires care about which case/context each link refers to.
-
Boundaries are often messy: system boundaries are frequently loose/implicit; mapping can proceed, but ambiguity must be managed rather than hidden.
-
Causal mapping in evaluation = 3 tasks (workflow):
- Task 1 — Gather narrative causal material: interviews, open-ended survey questions, document/literature review, archives/secondary text, or consensus processes (e.g., Delphi, participatory systems mapping). Elicitation may use back-chaining (“what influenced X?”) and forward-chaining (“what followed/could follow?”). Question framing affects factor semantics (e.g., QuIP tends to elicit changes like “reduced hunger” rather than variables).
- Task 2 — Code causal claims (“causal QDA”): unlike standard thematic QDA (codes = concepts), causal QDA codes links: each highlighted quote yields an influence factor → consequence factor pair; factors mainly exist as endpoints of links. Labelling can be exploratory/inductive (curate a common vocabulary across sources) or confirmatory (codebook from a ToC/prior work), with sequencing cautions to reduce framing/bias. Manual coding is costly; partial automation via NLP/ML is possible but not the focus.
-
Task 3 — Answer evaluation questions using the link database: global maps become “hairballs”, so analysis should generate selective maps aligned to questions (e.g., consequences of an intervention; causes of a valued outcome). Techniques include bundling co-terminal links (thickness/count), producing frequency-based overview maps (caution: rare-but-important links), rolling-up hierarchical factor taxonomies (with caveats), and limited quantitative summaries (warning: sensitive to coding granularity).
-
Limits / risks:
- Inference depends on source credibility: stronger conclusions require explicit, context-specific rules of inference (e.g., independent mentions threshold + theoretical plausibility + bias-mitigation steps).
- Effect strength/type is hard to capture: respondents rarely provide consistent magnitudes/necessity/sufficiency/certainty; forcing weights risks spurious precision.
-
Transitivity is both payoff and trap: inferring (C \rightarrow E) from (C \rightarrow D) and (D \rightarrow E) is powerful for indirect effects, but can be invalid when links come from non-overlapping contexts; valid inference requires attention to the intersection of contexts.
-
Concrete analytic contributions highlighted:
- Treat diagrams as an index into the underlying corpus: tool support should allow tracing from any link/factor back to transcript excerpts + source metadata.
-
Quantify robustness of evidence-based “arguments” along paths using maximum flow / minimum cut on the causal-claim network (how many claims would need removal to eliminate all paths between (C) and (E)), plus source thread count (how many distinct sources each provide a complete path).
-
Conclusion / evaluator-facing payoff:
- Helps evaluators (i) assemble narrative evidence about intervention and contextual influences (direct/indirect, intended/unintended), (ii) search/summarise/select quotations systematically, (iii) increase transparency/peer-reviewability of qualitative causal reasoning, (iv) communicate complexity with readable graphics.
- Key discipline is a two-step separation: first assemble and organise causal evidence; then judge what is actually happening—avoiding premature constraint of data collection to fit a prior ToC that stakeholders may not share.
References
Powell, Copestake, & Remnant (2024). Causal Mapping for Evaluators. https://doi.org/10.1177/13563890231196601.