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Predictive Methods

Bell Eapen edited this page Nov 10, 2025 · 1 revision

Predictive Methods

Overview

Predictive methods in CRISP-T encompass supervised and unsupervised machine learning algorithms applied to the numeric (and optionally text-derived) portion of the corpus. Their role within triangulation is to quantify patterns that can be cross-validated against qualitative insights (topics, categories, memos). Prediction is thus positioned as confirmatory rather than exploratory.

Implemented Techniques

Category Methods Purpose
Supervised Classification Decision Trees (--cart), K-Nearest Neighbors (--knn), Support Vector Machines (--cls), Neural Networks (--nnet), LSTM Text Classification (--lstm) Outcome prediction, rule extraction, pattern confirmation
Regression Linear/Logistic (--regression) Association strength, directionality
Clustering K-Means (--kmeans), Numeric clustering metadata Structure discovery, group comparison
Dimensionality Reduction PCA (--pca) Latent structure, variance concentration
Association Analysis Apriori rules (MCP association_rules) Co-occurring feature sets
Topological Data Analysis TDABM (--tdabm via crispt/crispviz) Shape and connectivity of high-dimensional data

Workflow Integration

  1. Perform textual analysis: topics (--topics), summarization, sentiment.
  2. Generate predictive models: crisp --inp corpus_folder --ml --cart --regression --kmeans --pca --out corpus_folder.
  3. Extract metadata (e.g., decision_tree_feature_importance, regression_coefficients).
  4. Triangulate: compare high-importance variables with recurring narrative themes.
  5. Refine grounded theory categories: corroborate or challenge initial qualitative constructs.

Sense-making Use Cases

Business Example

In sales enablement data, clustering reveals a segment with high training_hours and low time_to_first_deal. Decision tree rules highlight api_errors_rate as discriminative for churn. Narratives coded with theme "technical friction" overlap this segment, producing multi-modal evidence supporting a theory of tooling reliability driving retention.

Medical Example

Clinical + narrative dataset on chronic fatigue: PCA concentrates variance in components loading on sleep_balance and inflammation_marker. Logistic regression finds both significant for high_fatigue. Topics about "unrestful sleep" triangulate quantitatively and qualitatively, strengthening a code about inflammatory-sleep interaction.

Interpreting Outputs

  • Feature importance: treat as hypothesis-supporting signals, not causal proof.
  • Clusters: examine distribution of narrative keywords within each numeric cluster.
  • PCA components: map loadings > |0.4| to textual themes mentioning those constructs.
  • Association rules: interpret high-confidence itemsets alongside narratives referencing joint occurrences.

Limitations

  • Small sample sizes undermine statistical stability.
  • High-dimensional sparse text-derived features may inflate variance.
  • Predictive success without qualitative corroboration risks atheoretical modeling.

Best Practices

  • Maintain an audit trail: record CLI commands and outputs as memos.
  • Use semantic search (--semantic) to pull exemplar documents for numeric findings.
  • Avoid premature theoretical closure; treat conflicting model signals as prompts for further qualitative comparison.

References

  • Mettler et al. (2025) — Guidance on computational text methods in qualitative IS research.
  • Rudkin & Dlotko (2024) — Structural exploration via Ball Mapper.

See Also

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