William Gieng

William Gieng

Staff Data Scientist, Qualtrics

Portfolio

Decision science for ambiguous business questions.

Staff-level data scientist focused on causal inference, experimentation, and the translation of statistical evidence into senior leadership decisions.

Selected work

01 — Retention

Acquisition quality vs. durable value: a multi-method retention diagnosis

When a competitor disruption drove a 280K subscriber spike, was it real growth or borrowed users? Three independent lenses on the same question.

Survival analysis Segmentation LLM VOC

Decision impact

Reframed leadership conversation from acquisition volume to activation quality and retained LTV.

02 — Prediction

Subscriber churn prediction: survival curves and early engagement signals

Can first-month behavior separate "binge and leave" users from habit builders? Acquisition channel, billing, and engagement decomposition.

Survival curves Cohort analysis Classification

Decision impact

Surfaced channel-level churn risk and "binge and leave" patterns informing onboarding and acquisition spend.

Published writing

Towards Data Science Article

When customers churn at renewal: was it the price or the project?

Separating overlapping churn drivers when promo expiry and use-case completion arrive together.

Towards Data Science Article

LLM summarizers skip the identification step

Connecting LLM summarization failures to causal identification discipline.

Tools

quasi-experimental-pricing

DiD, synthetic control, RDD, and ITS on a synthetic subscription pricing dataset, with LTV translation and breakeven price calculation.

Python Causal inference DiD

transcript-analysis-pipeline

Three-stage LLM pipeline (extract, synthesize, audit) for decision-grade meeting analysis with explicit grounding and bounded fabrication controls.

Python LLM Evaluation

llm-churn-reason-mining

Pipeline that extracts and categorizes churn reasons from unstructured text using weak supervision, transformer fine-tuning, and prompt-engineered LLM summaries.

Python Transformers LLM

Decision science notes

A LinkedIn series on the framing decisions that determine whether analysis is causal.

Series · 01

Description, prediction, and causation answer different questions

Teams confuse the three and end up making confident decisions on the wrong analytical foundation.

Series · 02

Strong teams reason about the counterfactual, not just the outcome

Leadership in data work is making counterfactual assumptions explicit, especially when you can't run an experiment.

Series · 03

Not every correlation is a lever

Teams scale the wrong strategy when they treat correlations as causal mechanisms. Signal, symptom, and lever are different.