Erika Barker — Data Science & Data Journalismhttps://erikabarker.ai/Investigating how AI is reshaping our modern world.en-usFri, 23 Oct 2026 21:28:03 GMT What My Z-Score Indicator Taught Me About Chasing Better Numbershttps://erikabarker.ai/data-analysis/z-score-indicator-lessons/https://erikabarker.ai/data-analysis/z-score-indicator-lessons/What moving from HMA to KAMA taught me about Z-scores, backtest overfitting, market regimes, and the limits of better-looking results.Fri, 23 Oct 2026 19:54:01 GMTErika BarkerDataFinance AI infrastructure: separating investment risk from a bubble storyhttps://erikabarker.ai/finance/the-ai-bubble-anatomy-an-end-to-end-analysis-of-structural-risk-and-capital-decay/https://erikabarker.ai/finance/the-ai-bubble-anatomy-an-end-to-end-analysis-of-structural-risk-and-capital-decay/How to examine AI capital spending, depreciation, cash flows and power constraints without treating a plausible risk scenario as a proven collapse.Mon, 19 Jan 2026 05:01:33 GMTErika BarkerFinance From market mood to Regime Analyticshttps://erikabarker.ai/finance/i-built-a-serverless-dashboard-that-predicts-market-mood/https://erikabarker.ai/finance/i-built-a-serverless-dashboard-that-predicts-market-mood/The retired economic-dashboard prototype that helped shape Erika Barker’s interest in predictive analytics and statistical market regimes.Thu, 25 Sep 2025 15:19:07 GMTErika BarkerFinanceProjects Palantir and the price of moving fasterhttps://erikabarker.ai/data-analysis/the-palantir-paradox-democracys-most-dangerous-servant/https://erikabarker.ai/data-analysis/the-palantir-paradox-democracys-most-dangerous-servant/My military procurement experience helps me understand Palantir’s appeal. It also leaves me asking what faster decisions cost democratic accountability.Sat, 28 Jun 2025 14:48:51 GMTErika BarkerDataCulture What the data says about the American middle classhttps://erikabarker.ai/culture/the-shrinking-middle-class-will-america-collapse-by-2032/https://erikabarker.ai/culture/the-shrinking-middle-class-will-america-collapse-by-2032/How to interpret changes in middle-income population share without confusing income, wealth, money velocity or a prediction of national collapse.Sun, 16 Feb 2025 17:09:15 GMTErika BarkerCultureDataFinanceTech & AI Gradient boosting: how the trees learn togetherhttps://erikabarker.ai/tech/why-gradient-boosting-decision-trees-are-taking-over-data-science-and-why-you-should-care/https://erikabarker.ai/tech/why-gradient-boosting-decision-trees-are-taking-over-data-science-and-why-you-should-care/An explanation of boosting, loss functions and regularization, with practical limits on interpretability and financial-model evaluation.Tue, 07 Jan 2025 21:14:54 GMTErika BarkerTech & AIData Miami housing risk: what the data can actually showhttps://erikabarker.ai/finance/is-miamis-economic-bubble-about-to-burst-housing-remote-work-and-key-market-risks-analyzed/https://erikabarker.ai/finance/is-miamis-economic-bubble-about-to-burst-housing-remote-work-and-key-market-risks-analyzed/How to evaluate Miami housing affordability, inventory and local economic conditions without inventing a crash probability.Wed, 25 Sep 2024 15:49:44 GMTErika BarkerFinanceData Comparing the US and China: measure before forecastinghttps://erikabarker.ai/finance/us-china-economic-dynamics/https://erikabarker.ai/finance/us-china-economic-dynamics/A framework for comparing economic output, financial markets and cross-border investment without treating them as interchangeable measures.Thu, 29 Aug 2024 17:02:02 GMTErika BarkerFinanceMathematics Composite market scores: useful summaries, fragile assumptionshttps://erikabarker.ai/finance/composite-scoring-for-market-analysis/https://erikabarker.ai/finance/composite-scoring-for-market-analysis/How to normalize market indicators, expose weights and test a composite without confusing ETF prices, overlapping holdings or retrospective fit.Mon, 05 Aug 2024 19:52:01 GMTErika BarkerFinanceData Quantitative analyst vs. data scientist: compare the workhttps://erikabarker.ai/finance/what-is-a-quantitative-analyst-how-are-they-different-from-a-data-scientist/https://erikabarker.ai/finance/what-is-a-quantitative-analyst-how-are-they-different-from-a-data-scientist/How quantitative finance and data science overlap, where their objectives differ, and what evidence makes a portfolio useful to a hiring team.Wed, 05 Jun 2024 18:36:17 GMTErika BarkerFinanceMathematics Editorial standards and how this site uses AIhttps://erikabarker.ai/tech/how-this-site-uses-ai/https://erikabarker.ai/tech/how-this-site-uses-ai/How Erika Barker’s site distinguishes sources, analysis, experiments and AI assistance, and how substantive corrections are recorded.Mon, 27 May 2024 17:15:15 GMTErika BarkerTech & AIProjects My HMA Z-score indicator: distance is not probabilityhttps://erikabarker.ai/data-analysis/my-zscore-indicator-with-hma/https://erikabarker.ai/data-analysis/my-zscore-indicator-with-hma/A project note on standardizing a Hull moving average, the limits of normal-distribution interpretations and what a trading validation would require.Sun, 26 May 2024 15:38:41 GMTErika BarkerDataFinanceProjects What running taught me about doing enoughhttps://erikabarker.ai/culture/how-running-helped-my-depression-and-adhd/https://erikabarker.ai/culture/how-running-helped-my-depression-and-adhd/Running helped me manage anxiety, ADHD and the isolation of the pandemic. Then I learned when a useful routine could become another way to avoid my life.Sat, 25 May 2024 15:39:31 GMTErika BarkerCulture Conformal abstention: when a language model should declinehttps://erikabarker.ai/tech/deepminds-new-approach-to-avoiding-hallucinations-in-large-language-models/https://erikabarker.ai/tech/deepminds-new-approach-to-avoiding-hallucinations-in-large-language-models/What the 2024 conformal-abstention paper proposes, how calibration enters the method, and why statistical error control is not a guarantee of truth.Thu, 23 May 2024 18:16:54 GMTErika BarkerTech & AI Kernel methods in machine learning and financehttps://erikabarker.ai/data-analysis/how-kernel-methods-work-in-ml-and-finance/https://erikabarker.ai/data-analysis/how-kernel-methods-work-in-ml-and-finance/How kernels represent similarity, what an RBF kernel does, and how to evaluate a nonlinear model without confusing a flexible fit with predictive evidence.Thu, 23 May 2024 16:19:18 GMTErika BarkerDataFinanceMathematicsTech & AI Why I like the Hull moving averagehttps://erikabarker.ai/data-analysis/why-i-love-the-hull-moving-average-hma/https://erikabarker.ai/data-analysis/why-i-love-the-hull-moving-average-hma/How Alan Hull’s moving average combines weighted averages, where the square-root window enters, and why a responsive line is not a trading edge.Thu, 23 May 2024 14:59:40 GMTErika BarkerDataFinanceMathematics What the Riemann hypothesis actually sayshttps://erikabarker.ai/tech/what-is-the-riemann-hypothesis/https://erikabarker.ai/tech/what-is-the-riemann-hypothesis/An introduction to the zeta function, prime numbers and the limits of what a proof of the Riemann hypothesis would establish.Thu, 23 May 2024 03:29:44 GMTErika BarkerTech & AIMathematics Markov chains, explained with a two-state examplehttps://erikabarker.ai/data-analysis/2524/https://erikabarker.ai/data-analysis/2524/A complete transition-matrix example, a stationary distribution and the assumptions that limit Markov models in economic and financial research.Wed, 15 May 2024 01:46:16 GMTErika BarkerDataFinanceMathematicsTech & AI Game theory and markets: what Nash equilibrium explainshttps://erikabarker.ai/mathematics/how-did-game-theory-power-jim-simons-medallion-fund/https://erikabarker.ai/mathematics/how-did-game-theory-power-jim-simons-medallion-fund/A practical introduction to strategic incentives and Nash equilibrium, with a clear boundary between public mathematics and conjecture about private trading strategies.Sat, 11 May 2024 19:29:27 GMTErika BarkerMathematicsDataFinance Understanding the economy without misleading plumbinghttps://erikabarker.ai/finance/understanding-the-economy-money-flow-federal-reserve-and-financial-strategies/https://erikabarker.ai/finance/understanding-the-economy-money-flow-federal-reserve-and-financial-strategies/A guide to GDP accounting, money, credit and inflation that separates useful metaphors from causal claims.Fri, 03 May 2024 19:15:55 GMTErika BarkerFinance Making AI-assisted data work easier to verifyhttps://erikabarker.ai/tech/chat-gpt-efficiency/https://erikabarker.ai/tech/chat-gpt-efficiency/A practical workflow for dividing research tasks, checking generated code and distinguishing a model’s answer from evidence.Thu, 11 Apr 2024 23:41:15 GMTErika BarkerTech & AI The law of large numbers—and the stories it cannot provehttps://erikabarker.ai/mathematics/understanding-law-of-large-numbers-applications/https://erikabarker.ai/mathematics/understanding-law-of-large-numbers-applications/Why sample averages can stabilize, why repeated trials do not erase selection bias, and how a perfect prediction record can be manufactured.Thu, 07 Mar 2024 18:09:00 GMTErika BarkerMathematicsData How binary represents numbers, text and instructionshttps://erikabarker.ai/videos/how-binary-code-makes-computers-work/https://erikabarker.ai/videos/how-binary-code-makes-computers-work/Bits do not come with built-in meaning. A short guide to binary numbers, character encodings and the role of conventions in computing.Thu, 07 Mar 2024 04:24:18 GMTErika BarkerVideos