Boundary Condition Mapping¶

Why It Matters¶

Universal laws are rare outside physics. Most effects are conditional: antibiotics work on bacteria but not viruses; priming effects appear in some contexts but not others; management practices effective in manufacturing fail in creative work. Mapping boundaries prevents over-generalization and reveals moderating variables that point toward mechanism. "It depends" is only uninformative if you don't specify what it depends on.

The Key Move¶

After establishing an effect exists in one context, systematically vary contextual factors: population demographics, environmental conditions, temporal factors, measurement methods. Look for moderators - variables that strengthen, weaken, or reverse the effect. Document where the effect replicates and where it fails. The pattern of successes and failures reveals the theoretical boundary.

Classic Application¶

Drug efficacy varies by patient subgroups. Antidepressants work better for severe depression than mild. Chemotherapy effectiveness depends on cancer type, stage, and genetic markers. Clinical trials must map these boundaries through subgroup analyses and subsequent targeted trials. The prescription "works for depression" is too vague; "works for moderate-to-severe depression in adults without comorbid anxiety" is actionable.

Surprising Application¶

Learning techniques and study strategies. Spaced repetition improves recall - but for which material? Mapping reveals it works better for declarative facts than motor skills, better for recognition than generation, better with longer retention intervals. Testing yourself works - but not for novel problem-solving, better for retrieval than encoding. Understanding boundaries lets you match technique to goal.

Failure Modes¶

Giving up after one failed replication without investigating why. Assuming failure means the original was wrong rather than boundary-limited. Mapping boundaries unsystematically (testing random variations rather than theoretically motivated moderators). Treating boundaries as failures rather than as crucial theoretical information about mechanism.

Go Deeper¶

Simons, Shoda, & Lindsay (2017), "Constraints on generality (COG): A proposed addition to all empirical papers," Perspectives on Psychological Science 12(6); Cronbach, L.J. (1975), "Beyond the two disciplines of scientific psychology," American Psychologist 30(2).