Tool methodologies.

Each tool methodology page exists for one reason: to give curious users, researchers, and skeptics complete visibility into how a tool produces its result. We document the validated framework being implemented, the exact items or variables measured, the scoring algorithm in plain math, the reference data and benchmarks, the known limitations, and the peer-reviewed sources backing each claim.

The methodologies below are organized by lab. Each links to a substantive ~1,500 to 2,500-word reference page suitable for citation in academic and clinical contexts. Each is independently reviewed by Eskezeia Y. Dessie, PhD.

• Brain Age Index — Lancet Commission framework, 12 modifiable risk factors, population-attributable fractions for brain-age estimation.
• Sleep-Cognition Optimizer — chronotype assessment + 90-minute ultradian sleep-cycle architecture for personalized sleep timing.
• Cognitive Reserve Estimator — Stern (2002, 2009) cognitive-reserve framework, multi-domain weighted scoring, age-stratified percentile bands.
• Chronotype Test — Horne–Östberg MEQ (1976) and reduced MEQ (Adan & Almirall 1991), 5 chronotype categories, sleep-timing recommendations.
• Adult ADHD Test — LBL Adult ADHD Symptom Inventory v1.0, 18 LBL-original items operationalizing DSM-5 ADHD criteria, 4 severity bands anchored to Kessler 2007 strata, 5 archetypes, comorbidity epidemiology.
• Adult Autism Self-Inventory — RAADS-14 (Eriksson 2013, CC BY 2.0), 14-item factor-analytic short form, three subscales (Mentalizing/Social/Sensory), 4 severity bands, 5 archetypes with first-match-wins routing, Lai 2019 comorbidity panel, Cassidy 2014 care-aware framing.

• Cognitive Bias Susceptibility — an LBL-original battery for measuring individual susceptibility to systematic reasoning errors, grounded in the heuristics-and-biases and rational-thinking literature.
• Big Five Personality Snapshot — public-domain 30-item IPIP (Mini-IPIP plus IPIP-FFM), 5-trait OCEAN scoring, reference-value bands.

• Should I Quit? — Lee-Mitchell Unfolding Model of Turnover applied to high-stakes stay-vs-go decisions.
• Career Pivot Decision Matrix — Career-capital framework (Newport 2012; Savickas 2012), multi-criteria weighted scoring, 4-quadrant decision archetype.

• Flourishing Index — LBL-original 16-dimension framework (9 core + 7 contextual), 25 items, 6 archetypes; Global Flourishing Study (VanderWeele et al. 2025) Wave 1 normative benchmarks.
• Attachment Style Decoder — LBL-original 20-item instrument grounded in the two-factor adult attachment framework (Brennan, Clark & Shaver 1998; Mikulincer & Shaver 2007), four-archetype scoring with 4.0 cutoff rationale.
• Meaning in Life Questionnaire
  Life Dashboard

  LBL Depression Test methodology

  9-item depression screener (Kroenke 2001) — instrument, 5 severity bands, sub-dimension symptom profile, item-9 hard-escalation modal, 5 archetypes, validation, and documented author choices.

  — MLQ (Steger, Frazier, Oishi & Kaler 2006), 2-subscale design, 2×2 quadrant interpretation, normative percentile bands.

Every tool methodology follows a consistent template, so users always know where to find the information they want:

• What this tool measures — the construct or constructs being assessed.
• Why it matters — the empirical case for why this measurement is worth making.
• The validated framework we implement — the specific peer-reviewed instrument or model being used.
• How the score is computed — the algorithm in plain math, including any reverse coding, weighting, or cutoff rules.
• Key variables and how each is measured — for each input, what it captures and how.
• Reference data and benchmarks — the populations and norming data the tool compares against.
• Limitations — what the tool does and does not capture, including sampling limits, instrument biases, and the dimensional-vs-categorical caveats.
• Independent analytical review — reviewer credit and the scope of methodological review.
• Version log — significant methodology changes are versioned and dated.
• Selected references — full peer-reviewed citation list with DOIs.
• Key terms — cross-links to relevant glossary entries.

Methodology pages are author-byline content written by Abiot Y. Derbie, PhD, with independent analytical review by Eskezeia Y. Dessie, PhD. Every claim that exceeds general public knowledge is sourced to a peer-reviewed citation. Every algorithm, cutoff, and benchmark used in a tool is documented on the corresponding methodology page in sufficient detail for a researcher to replicate or critique.

For the broader editorial framework that governs how LifeByLogic content is sourced, reviewed, and corrected, see the Editorial Policy. For terms used across these methodologies, see the Glossary.