Use when conducting the constant comparative method — comparing incidents to incidents, incidents to concepts, and concepts to concepts.
The constant comparative method is the engine of classic grounded theory. It converts raw experience into concepts and concepts into theory by systematic comparison. Without comparison, coding collapses into summary; with comparison, coding becomes analytic.
Use this skill whenever you are generating codes, merging categories, defining properties/dimensions, testing a core category, or evaluating saturation claims.
Classic texts describe comparing as progressing through comparing incidents applicable to each category, integrating categories and their properties, delimiting the theory, and writing theory. In practice, these overlap—but the sequence is still pedagogically useful.
Goal: Ensure a code is conceptually consistent and data-grounded.
Micro-procedure:
Output: tighter definitions; early properties (“kinds of delaying,” “degrees of delaying”).
Goal: Use new data to test the conceptual label.
Micro-procedure:
Output: dimensional thinking; boundary conditions; negative cases queued.
Goal: Build relationship statements among categories.
Micro-procedure:
Output: contingent hypotheses; later fodder for theoretical coding.
Goal: Stop expanding sideways; deepen core-related comparisons.
Micro-procedure:
Output: theoretical density without endless sprawl.
| Level | Question | Typical yield |
|---|---|---|
| Incident ↔ incident | “Same meaning?” | Code splits/merges |
| Incident ↔ concept | “Still fits?” | Property/dimension refinement |
| Concept ↔ concept | “How connected?” | Hypotheses + theoretical codes |
| Model ↔ negative case | “Where breaks?” | Boundary conditions |
Take two incidents that look opposite. Force yourself to name the conceptual axis that distinguishes them (a dimension).
Select extremes within your sample (if available). Ask what conditions produce the difference.
Ask: “Who is not represented here?” Negative cases may be data absences—note as a sampling issue, not only analytic failure.
Compare interview claims to observation or documents where possible. Treat discrepancies as analytic gold.
Compare early vs late interview moments within a longitudinal account (if applicable).
Category: ________
Incident ID | Evidence snippet | Candidate property | Notes |
Hypothesis: If [condition], then [strategy], leading to [outcome].
Supporting incidents (IDs):
Contradicting incidents (IDs):
Revised hypothesis:
Code A vs Code B:
Similarities:
Systematic differences:
Decision: merge / split / keep separate
Rationale (comparative evidence):
End each analytic session with:
Comparisons executed (brief list):
Code changes (rename/split/merge):
New/updated hypotheses (bullets):
Negative cases discovered:
Next comparison targets (specific incidents/sources):
This becomes part of your audit trail.
open-coding, selective-coding, memo-writingtheoretical-sampling, theoretical-saturationglaserian-grounded-theory