by Noah Green CPA CFE | May 7, 2026 | DD Tech Lab
First-order Markov modeling assumes the next state depends only on the current state, what happened one step ago tells you everything you need to know about what happens next. For most audit applications this is a useful approximation. For long-memory fraud schemes,...
by Noah Green CPA CFE | May 4, 2026 | DD Tech Lab
Coarse-band threshold testing catches major asymmetric clusters but misses two refinements requiring dedicated analysis. Bimodality (two distinct peaks in the distribution) means the file behaves as if two different payment systems were mixed together: a normal...
by Noah Green CPA CFE | Apr 30, 2026 | DD Tech Lab
Benford’s Law and first-order Markov anomaly detection are usually presented as separate tools. Practitioners run each in isolation, get two binary “deviation / no deviation” signals, and either use a single tool or take the OR of both. The...
by Noah Green CPA CFE | Apr 27, 2026 | DD Tech Lab
Management override of internal controls frequently manifests through journal-entry timing patterns. PCAOB AS 2401.A.5 identifies three temporal characteristics that elevate entries from routine to requiring substantive testing: entries posted on non-business days,...
by Noah Green CPA CFE | Apr 26, 2026 | DD Tech Lab
The methodology articles in this sub-series have used Neo4j as the working substrate. The choice is not accidental, Cypher is the most mature graph query language, the Neo4j Graph Data Science library has the broadest algorithm coverage, the APOC extension set covers...
by Noah Green CPA CFE | Apr 23, 2026 | DD Tech Lab
Public-company restatements do not arrive at a constant rate. They cluster, temporally (Sarbanes-Oxley wave 2004-2006, financial-crisis wave 2008-2010, revenue-recognition-standard wave 2018-2019) and cross-sectionally (industries with similar accounting complexity...
