Evidence Ledger #
Each global claim links here. Rows include the evidence class, domain, measurement, effect size, window, case bindings, sources, and confidence level.
How to read a row #
- Effect size reports the study-specific estimate or bounded outcome in the source’s unit, such as percentage points, standardized effects, counts, proficiency levels, or qualitative bounds
- Window is explicit (for example D0-D7)
- Evidence class uses the five classes defined in the Editorial Policy
- Case bindings identify public cases that cite the canonical ledger record
- Sources link to a case write-up and raw data when possible
| ID | Evidence class | Claim | Domain | Measure | Effect size | Window | Confidence | Case bindings | Sources |
|---|---|---|---|---|---|---|---|---|---|
| BS-0001 | Observational case | The case library uses behavior-first validation as a planning principle across documented examples. | Cross-industry | Presence of the planning principle across case interpretations | Qualitative synthesis only; no comparative effect estimate | Project-specific | Working | None | Case |
| BS-0002 | Illustration | The measurement guide illustrates how to test whether shorter time to first target behavior predicts higher medium-term retention. | Consumer and SaaS | Minutes to first target behavior vs 90-day behavior retention | Product- and cohort-specific (validate per segment; no single published effect size) | Baseline to 90 days (or product-specific) | Working | None | Method |
| BS-0003 | Comparative test | At-scale nudge-unit RCTs show small average effects (~1.4 pp), far below academic journal averages (~8.7 pp). | Public sector and enterprise | Average percentage-point change in target outcome across large RCTs | ~1.4 pp average (vs ~8.7 pp in academic journals) | 126 RCTs; 23 million individuals | High | None | Study |
| BS-0004 | Comparative test | Opt-out (default) organ donation regimes do not reliably increase transplantation; complementary system investments drive outcomes. | Healthcare policy | Deceased and living donor rates; transplant rates | No reliable increase in deceased donation after opt-out policy shifts; some evidence of decreased living donation (−29%) | Cross-national, multi-year comparisons | High | Case | Review, Study, Study |
| BS-0005 | Observational case | Instagram pivoted from check-ins to photo sharing after observing how early users behaved, and the change preceded rapid reported user growth. | Technology | Reported sign-up and user counts; no active-user, photo-post completion, or retention rate established | 25,000 sign-ups on launch day (Systrom, CBS, 2015); 7 million users within nine months (Fortune, 2014). No time-to-first-post measurement or causal effect estimate. | Launch day through the first nine months | Working | None | Interview, Podcast, Interview |
| BS-0006 | Observational case | Slack’s founder reported invitation requests and continued use among teams that had exchanged 2,000 messages; its 2019 S-1 reports aggregate message activity and net dollar retention. | Enterprise software | Invitation requests, selected-team continued use, aggregate messages and revenue retention; distinct measures with different denominators | 8,000 preview invitation requests on day one and 15,000 after two weeks; 93% continued use among teams crossing 2,000 messages; over 1 billion messages in the week ended January 31, 2019 and 143% net dollar retention as of that date | August 2013 preview requests; selected-team status at the 2015 interview; January 2019 filing metrics | Working | Case | Founder interview, Company filing |
| BS-0007 | Comparative test | Studies of M-PESA in Kenya report risk-sharing and poverty-related estimates under their respective study designs; these do not isolate removal of an environmental bottleneck as the sole mechanism. | Finance / Emerging markets | Adoption %, transactions, poverty outcomes | ~194,000 households (2%) lifted out of poverty in Kenya (study estimate); improved risk-sharing and consumption smoothing | Multi-year (Kenya; study periods vary) | High | Case | Study, Study |
| BS-0008 | Observational case | Spotify reports sustained, large-scale use of Discover Weekly, a personalized automated discovery feature; aggregate milestones do not estimate incremental lift. | Technology / Media | Cumulative Discover Weekly listening hours and tracks; weekly new-artist discoveries | 2.3 billion listening hours from 2015-2020; more than 100 billion tracks streamed through the feature and 56 million new artist discoveries per week by 2025 (company-reported) | 2015-2025 company milestones | Working | Case | Company post, Company post, Company post |
| BS-0009 | Observational case | An observational study recruited 225 adult Duolingo Spanish or French beginning-course completers with U.S. IP addresses who self-reported little or no prior proficiency and no concurrent language classes, programs, or apps; 220 supplied reading scores and 220 supplied listening scores, and speaking and writing were not assessed. | Education / EdTech | ACTFL Reading Proficiency Test and Listening Proficiency Test scores; logged Duolingo learning time | Spanish: Intermediate Low reading (n=132) and approaching Novice High listening (n=131). French: approaching Intermediate Mid reading (n=88) and Novice High listening (n=89). No concurrent comparison group or causal estimate. | Mean 562 calendar days for Spanish and 634 days for French from first target-language lesson to study participation; median 112 logged learning hours overall | Working | Case | Study |
| BS-0010 | Observational case | Zoom reported daily meeting participants rising from 10 million to 300 million from December 2019 to April 2020 as pandemic restrictions coincided with rapid expansion of remote activity; the pattern does not isolate the effect of access friction. | Enterprise / Communication | Daily participants, join TTFB | 10M → 300M daily participants (Dec 2019-Apr 2020); TTFB near-instant | Q1-Q2 2020 | Working | Case | Company post |
| BS-0011 | Comparative test | Meta-analyses of choice architecture interventions show small-to-medium average effects with substantial heterogeneity and publication bias. | Cross-domain meta-analysis | Cohen’s d across published and unpublished studies | d ≈ 0.43-0.45 (small-to-medium) | 214 publications; 455 effect sizes | High | None | Meta-analysis |
| BS-0012 | Comparative test | Across five field experiments at one large organization, Study 1 produced a small increase in carpool registration but no increase in active carpooling; Studies 2, 3a, 3b, and 4 found no positive effect on active carpooling, discounted transit-pass purchases, or single-occupancy-vehicle commuting. | Transportation / Public policy | Carpool registration and activation; discounted transit-pass purchases; self-reported single-occupancy-vehicle commute days | Study 1 registration was 0.05% in control versus 0.22% with a letter (d=0.055, P<0.001), but only seven participants became active carpoolers, four in control. Effects in Studies 2, 3a, 3b, and 4 were d=0.00, -0.01, -0.01, and 0.01 and were statistically equivalent to zero under post-hoc bounds set to each study’s 80%-power minimum detectable effect. | Study 1: two months; Study 2: four weeks; Study 3a: one-week trial plus one-month follow-up; Study 3b: one month; Study 4: baseline to one month after the final travel-plan session | Working | None | RCT |
| BS-0013 | Comparative test | Home energy reports (Opower) generate small, persistent behavior changes; effects are modest and context-dependent. | Energy / Residential | kWh reduction vs baseline/cohort | Small average reductions; persistence with decay (10-20% decay/year after reports stop) | 12-24 months | High | None | RCT |
| BS-0014 | Observational case | Robinhood’s zero-commission model removed transaction fees, and its filing reports adoption among many first-time investors; the observational record does not isolate fee removal as the cause. | Finance | New account openings, first-time investors, transaction frequency | Large platform growth; industry-wide fee elimination followed | 2013-2019 | Working | Case | Industry |
| BS-0015 | Comparative test | Reputation and trust systems (Airbnb) enable high-stakes sharing behaviors; conversion improves when trust cues are salient. | Technology / Marketplaces | Listing conversion, booking behaviors | Conversion deltas vary by study; generally positive | 12-36 months | Working | Case | Experiment |
| BS-0016 | Illustration | Behavioral public strategy connects micro-foundations (individuals, teams, tools) to meso-level performance; simple nudges are brittle without system design. | Public policy | Conceptual framework (peer-reviewed) | Not applicable; conceptual synthesis | Not applicable | High | None | Article |
| BS-0017 | Observational case | Reviews find that measurement windows and cadence are associated with what longitudinal studies detect and recommend explicit temporal hypotheses. | Methods / Measurement | Meta-analytic conclusion | Not applicable; meta-analysis of temporal aspects | Not applicable | High | None | Meta-analysis, Review |
| BS-0018 | Observational case | Self-identity explains additional variance in behavioral intentions beyond attitudes, subjective norms, and perceived behavioral control (TPB). | Psychology / Theory | Meta-analytic correlation (r) and incremental R² | r+ = 0.47; ΔR² ≈ 6% (intention) and 9% (identity) beyond TPB components | 40 independent tests; N = 11,607 | High | None | Meta-analysis |
| BS-0019 | Illustration | Minimum-component (bottleneck) logic: the lowest-scoring determinant constrains behavior; addressing bottleneck components is necessary for reliable change. | Methods / Theory | Conceptual (model-based) | Not applicable | Not applicable | High | None | Model |
| BS-0020 | Comparative test | Values-affirmation (identity-aligned) interventions yield durable academic benefits versus reminders alone. | Education | Longitudinal academic outcomes | Context-dependent; durable effects reported in field studies | Multi-year | Working | None | Field |
| BS-0021 | Comparative test | Psychological targeting (personality-tailored messaging) outperforms generic messaging for persuasion and conversion. | Marketing / Persuasion | Conversion/lift vs. generic controls | Positive treatment effects; varies by context | Campaign-specific | Working | None | Experiment |
| BS-0022 | Observational case | In CB Insights’ startup post-mortem analysis, “no market need” is a top failure reason (#2). | |||||||
| Product / Strategy | Post-mortem analysis | 35% (ranked #2; CB Insights) | Various; cross-company | High | None | Report | |||
| BS-0023 | Illustration | The Fogg Behavior Model (B=MAP) established that behavior occurs when Motivation, Ability, and Prompt converge at the same moment. | Behavior Design / Theory | Published conceptual model | Defines Motivation, Ability, and Prompt as simultaneous conditions in the model; does not validate the later Behavior Fit Assessment | Since 2009 | High | None | Conference paper |
| BS-0024 | Observational case | Reviews of value-based decision making and action control distinguish proposed Pavlovian, habitual, and goal-directed systems with different computational and neural properties. | Behavioral Neuroscience | Review of computational accounts, neural evidence, and action-control research | Supports a qualified distinction among Pavlovian, habitual, and goal-directed control; does not imply that three simple systems universally govern every behavior | Established body of research | High | Case | Review, Review |
| BS-0025 | Observational case | Reviews and computational models distinguish goal-directed actions as outcome-sensitive and habitual actions as relatively insensitive to reward devaluation. | Behavioral Neuroscience | Outcome devaluation paradigm | Robust dissociation across human and animal studies | Established body of research | High | Case | Computational model, Review |
| BS-0026 | Observational case | The widely cited 66-day median came from a study of simple behaviors such as drinking water and does not establish a formation time for complex behaviors. | Habit Formation | Days to 95% automaticity | Median 66 days (range 18-254) | 84-day study | High | None | Longitudinal study |
| BS-0027 | Comparative test | Bias-corrected analyses find an aggregated nudge effect (d = 0.270) that drops to near zero (d = 0.004) after publication-bias adjustment. | Nudge Effectiveness | Cohen’s d (aggregated vs. bias-corrected) | d = 0.270 aggregate; d = 0.004 after publication-bias adjustment | 13 articles (14 meta-analyses); 1,638 primary studies; ~30M participants | High | None | Meta-analysis, Second-order meta-analysis |
| BS-0028 | Comparative test | Implementation intentions (if-then planning) improve goal achievement with medium-to-large effect size. | Behavior Planning | Cohen’s d | d = 0.65 (medium-large) | 94 studies, 8,000+ participants | High | None | Meta-analysis |
| BS-0029 | Comparative test | Intentions explain less than one-third of behavior variance; the intention-behavior gap is substantial and systematic. | Behavior Theory | Variance explained | TPB meta-analysis: ~27% of behavior variance explained; intention-change interventions shift intentions (d = 0.66) more than behavior (d = 0.36) | Meta-analyses across 185+ studies (TPB) and 47 experimental tests (intention → behavior) | High | None | Meta-analysis, Meta-analysis, Meta-analysis, Review |
| BS-0030 | Illustration | Behavior is predicted by attitudes, subjective norms, and perceived behavioral control (Theory of Planned Behavior). | Behavior Theory | Multi-factor prediction model | R² = 0.27-0.39 for intentions; varies for behavior | Foundational theory since 1991 | High | None | Theory paper |
| BS-0031 | Observational case | A review characterizes habits as responses cued by context and reports greater behavioral stability in stable contexts, chiefly for simple repeated behaviors. | Habit Formation | Context-behavior associations | Strong context effects for simple, repeated behaviors | Review synthesis | High | None | Review |
| BS-0032 | Observational case | Participants in an automatic-escalation savings program increased their saving rate from 3.5% to 13.6% over 40 months; this record is a before-and-after field pattern. | Finance / Behavior Design | Savings rate | Savings rates increased from 3.5% to 13.6% over 40 months | Multi-year longitudinal | High | Case | Field study |
| BS-0033 | Observational case | The 2007 review proposed that self-control draws on a limited resource that can be depleted by prior exertion; it did not test whether environmental design sustains behavior better than willpower. | Self-Regulation | Self-control performance after exertion | Significant depletion effects (though effect sizes debated in replications) | Meta-analytic synthesis | Working | None | Review |
| BS-0034 | Observational case | General cognitive ability (GCA) predicts job performance with corrected validity around r=0.22 in 21st-century samples. | Cognitive Ability / Work | Corrected validity correlation (r) | Observed r = 0.16; corrected r = 0.22 | 153 samples; N = 40,740 (21st-century) | High | None | Meta-analysis |
| BS-0035 | Observational case | Academic performance is jointly predicted by cognitive ability and Big Five traits; cognitive ability accounts for most of the explained variance; conscientiousness is the largest trait contributor. | Education / Psychometrics | Variance explained; relative importance | Combined explains 27.8% variance; cognitive ability 64% of explained variance; conscientiousness 28% | 267 samples; N = 413,074; 228 studies | High | None | Meta-analysis |
| BS-0036 | Observational case | Big Five traits predict performance across criteria; conscientiousness shows the most consistent positive association; other trait effects vary by performance category. | Personality / Performance | Meta-analytic correlations (ρ) across performance criteria | Overall: conscientiousness ρ = 0.19; extraversion ρ = 0.10; agreeableness ρ = 0.10; neuroticism ρ = −0.12; openness ρ = 0.13. Category-specific: −0.13 to 0.24 | 54 meta-analyses; k = 2,028; N = 554,778 | High | None | Meta-analysis |
| BS-0037 | Observational case | Big Five measures do not fully capture HEXACO scale variance; using Big Five instead of HEXACO entails a large loss of information. | Personality / Psychometrics | Cross-instrument scale variance capture | Large deficiency in capturing HEXACO variance (authors conclude loss comparable to discarding one Big Five scale) | Multiple Big Five measures compared with HEXACO-PI-R scales | High | None | Psychometrics |
| BS-0038 | Observational case | Psychometric analyses identify Honesty-Humility as a distinct factor, and models that separate it from classic agreeableness-related facets show better prediction of deceit-related variables. | Personality / Psychometrics | Factor relations; incremental prediction | Improved prediction reported for deceit-without-hostility variables after realignment | Lexical Big Five + Five-Factor Model facet realignment | High | None | Psychometrics |
| BS-0039 | Observational case | A meta-analysis found high rank-order stability of personality traits in adulthood, with higher estimates at older ages and values near 0.74 in later adulthood. | Personality / Psychometrics | Rank-order consistency (test-retest correlation) | r ≈ 0.74 (ages 50-70; ~6.7-year interval at peak) | 152 longitudinal studies; 3,217 test-retest coefficients | High | None | Meta-analysis |
| BS-0040 | Observational case | Exercise/physical-activity identity correlates with physical activity behavior across studies. | Health Behavior / Physical Activity | Meta-analytic correlation (r) | r = 0.44 | Meta-analysis across 62 datasets | High | None | Meta-analysis |
| BS-0041 | Observational case | Within an exercise RCT, measured increases in exercise identity were associated with physical activity at follow-up beyond treatment condition; conditions did not significantly differ in identity change. | Health Behavior / Maintenance | Minutes/week of moderate-to-vigorous physical activity (MVPA) at follow-up | b = 16.76 minutes/week per +1 identity point (95% CI: 2.36-31.15) | 16-week RCT + follow-up; N = 130 | Medium | None | RCT |
| BS-0042 | Observational case | Habit and identity measures are strongly correlated in health behaviors; this association is consistent with, but does not establish, a mutual-reinforcement hypothesis. | Health Behavior / Habit | Three-level meta-analytic correlation (r) | r = 0.55 (95% CI: 0.49-0.60) | 19 articles; N = 13,340 | High | None | Meta-analysis |
| BS-0045 | Observational case | Conscientiousness is consistently associated with healthier behavior patterns across health behavior domains. | Personality / Health Behavior | Meta-analytic correlations (r) across behaviors | r ≈ 0.05 (physical activity) to r ≈ −0.28 (drug use), directionally consistent across domains | 194 studies | High | None | Meta-analysis |
| BS-0046 | Comparative test | Personality traits can change via intervention, but average effects are modest and typically require sustained effort. | Personality / Change | Meta-analytic standardized mean difference (d) in trait change | Average trait change d ≈ 0.37 across interventions | 207 intervention studies; 20,653 participants | High | None | Meta-analysis |
| BS-0047 | Independent replication or evaluation | Personality-life outcome associations replicate at high rates in a preregistered, high-powered replication project (with expected direction and moderate effect-size shrinkage). | Personality / Replication | Replication rate and relative replication effect size | 87% of replications significant in expected direction; replication effect sizes averaged 77% of original effects | 78 replications across 4 samples; total N = 6,106 | High | None | Preregistered replication |
| BS-0048 | Observational case | Traits can be modeled as density distributions of states: people show substantial within-person variability, yet their average trait levels (distribution means) are highly stable/reliable within experience-sampling windows. | Personality / Psychometrics | Split-half stability of distribution means (“location stability”) | Location stability (Study 1, 2-week ESM): Extraversion 0.90, Agreeableness 0.94, Conscientiousness 0.87, Emotional Stability 0.90, Intellect 0.94 | Experience sampling over ~2 weeks; Study 1 N = 127 | High | None | Experience sampling |
| BS-0049 | Observational case | Conscientiousness is associated with lower mortality risk across longitudinal cohorts. | Personality / Health | Meta-analytic correlation (r) with mortality | r = −0.11 (95% CI: −0.13 to −0.09) | Meta-analysis of 20 independent samples | High | None | Meta-analysis |
| BS-0050 | Observational case | General mental ability is a strong predictor of performance in job training programs. | Cognitive Ability / Training | Meta-analytic validity correlation (r) | r ≈ 0.56 for job training performance | Meta-analytic synthesis (Schmidt & Hunter, 1998) | High | None | Meta-analysis |
| BS-0051 | Independent replication or evaluation | A preregistered, 39-lab replication did not support the classic induced-compliance (high-choice > low-choice) attitude-change effect. | Social Psychology / Replication | Attitude-change contrast (high choice vs low choice) | Primary high-choice vs low-choice prediction not supported; counterattitudinal vs neutral contrast supported | 39 labs; 19 countries; N = 4,898 | High | None | Multilab preregistered replication |
| BS-0052 | Observational case | A modern archival analysis concludes that key elements of the classic ‘When Prophecy Fails’ account were substantially inaccurate and involved serious ethical problems. | History / Research Integrity | Archival/historical reassessment | Not applicable | Archival analysis published 2026 | Medium | None | Historical analysis |
| BS-0053 | Observational case | A widely cited behavioral-ethics intervention paper on signature placement and honesty was retracted. | Behavioral Ethics / Retraction | Retraction notice | Not applicable | Retraction published 2021 (original 2012) | High | None | Retraction |
| BS-0054 | Comparative test | Automatic enrollment dramatically increases 401(k) participation among new hires and anchors many participants to default contribution rates and asset allocations. | Finance / Defaults | 401(k) participation rate; default contribution and investment choices | Participation at 3-15 months tenure: 86% (automatic enrollment) vs 37% (opt-in). Default contribution adherence declines from 92% to 57% over 15 months. | 3-15 months of tenure; up to 15 months post-hire | High | Case | Field study, Working paper |
| BS-0055 | Comparative test | Automatic enrollment can raise participation, but long-run retirement wealth effects can be modest after accounting for turnover and withdrawals. | Finance / Defaults | Long-run retirement savings / wealth accumulation | +0.6% of income in retirement savings; effects substantially smaller once accounting for job changes and cash-outs | Long-run model with turnover and withdrawals | Medium | Case | Working paper |
| BS-0056 | Comparative test | Experimental attempts to induce habits in humans often fail; extensive training may not produce outcome-insensitive (habitual) responding. | Habit Formation / Neuroscience | Outcome devaluation sensitivity after training | Five experiments reported failures to induce habitual responding in humans | Five experiments | High | None | Journal article |
| BS-0057 | Observational case | Acorns attaches automatic round-up contributions to card spending, and company and press sources report about $43 in average monthly contributions; they do not isolate an incremental effect. | FinTech / Personal finance | Average round-ups contribution per user; early contribution volume | Average round-ups: ~$43 per customer per month (reported); >$150 invested in first 4 months from round-ups alone (company-reported) | Monthly; first 4 months post-enablement | Working | Case | Company documentation, Company post, Press |
| BS-0058 | Observational case | YNAB centers active allocation before spending, while Mint centered passive tracking; the contrast is a hypothesis about durable budgeting behavior, not a comparative test. | FinTech / Personal finance | Product viability and sustained usage (qualitative); budgeting behavior cadence | Mint: 1.5M users at 2009 acquisition (reported) and later shutdown (2024). YNAB: sustained subscription model anchored in repeated allocation behavior. | 2007-2024 | Working | Case | Company documentation, Press, Press |
| BS-0059 | Observational case | ClassPass offered access to varied fitness venues rather than a single-gym commitment; its reported trajectory is consistent with, but does not test, a variety-seeking fit hypothesis. | Fitness / Marketplace | Subscriber retention proxies; repeat class attendance | Reported partner-side pattern: high share of visits are to new studios early; usage concentrates after initial exploration (company/partner reporting varies). | 2012-2018 (model evolution) | Working | Case | Press, Case write-up, Press |
| BS-0060 | Observational case | Gym members in transaction data often chose flat-fee contracts that cost more than pay-per-visit alternatives while attending infrequently and delaying cancellation; the authors interpret this pattern as overconfidence. | Behavioral Economics / Fitness | Attendance vs contract choice; cancellation delay | Members overestimated visits (~9.5 forecast vs ~4.2 actual/month); flat-fee members attended ~4.3x/month and paid an effective price >$17/visit (field data). | 3 years; N=7,752 members (3 US health clubs) | High | Case | Journal article |
| BS-0061 | Observational case | Peloton’s reported growth coincided with an at-home, instructor-led, socially reinforced model; adoption later shifted as pandemic conditions changed. | Fitness / Consumer subscription | Subscriber growth; engagement and churn (reported) | Hardware-subscriber engagement spiked during COVID and normalized afterward (reported). | 2018-2023 | Working | Case | Press, Press |
| BS-0062 | Observational case | In a longitudinal social-network study, receiving kudos was associated with modestly higher subsequent running frequency; Strava also uses social feedback and competition. | Fitness / Social platforms | Running frequency and peer influence | Receiving kudos is associated with increased running frequency (study of running clubs; magnitude context-specific); Strava reports 180M+ athletes in 185+ countries. | Study-specific (running clubs; longitudinal social network analysis) | Working | Case | Journal article, Company |
| BS-0063 | Observational case | A single-site observational study enrolled 110 participants in a modified, instructor-supported nine-week Couch-to-5K program. The paper’s abstract reports 27.3% completion, but its Results section reports 64.5% dropout and Figure 1 shows 39 completers (35.5%), so the completion rate is unresolved. | Fitness / Program design | Completion and dropout in a modified Couch-to-5K program; separate NHS app downloads and completed runs | Study-source conflict: 27.3% completion in the abstract versus 39 of 110 completers (35.5%) in Figure 1, consistent with 64.5% dropout in Results. Separately, NHS reported more than 7 million app downloads since 2016 and 8.7 million runs completed in 2024. | Modified nine-week program studied from May 2018 to May 2020; separate NHS app reporting through 2024 | Working | Case | Study, Government |
| BS-0064 | Observational case | Discord formalized team voice and text coordination for gaming groups and later reported adoption across broader communities; this sequence is consistent with an existing-behavior fit hypothesis. | Technology / Communication | Adoption and community usage (reported) | 200M+ global monthly active users (company-reported, 2025); expansion beyond gaming (reported). | 2015-2025 | Working | Case | Company, Reference |
| BS-0065 | Observational case | Figma offered real-time multiplayer editing for collaborative design workflows and later achieved broad adoption; source accounts describe less handoff work and same-file co-creation without a causal comparison. | Technology / Work tools | Workflow friction (qualitative); adoption (reported) | Real-time multiplayer editing reduced coordination overhead by eliminating export/sync/email file behaviors (mechanism; quantitative varies). | 2016-2023 | Working | Case | Company post, Press |
| BS-0066 | Observational case | TikTok says its For You feed ranks videos using user interactions and video information; follower count and prior high-performing videos are not direct ranking factors. | Technology / Social media | Creator output and consumption behavior (qualitative); adoption (reported) | Mechanism-level: recommendation feed makes reach less dependent on follower graphs; video-length flexibility expands viable content behaviors. | 2016-2024 | Working | Case | Company post |
| BS-0067 | Observational case | By its 2006 acquisition, YouTube allowed general video upload and sharing and reported more than 100 million daily views and 65,000 daily uploads; it added a revenue-sharing Partner Program in 2007. | Technology / Creator platforms | Upload and viewing volume at acquisition; creator incentives | At acquisition (reported): ~100M daily video views; ~65K new videos uploaded daily. | 2005-2007 | High | Case | Filing, Press |
| BS-0068 | Observational case | Netflix paired subscriptions with no late fees and reported rapid subscriber growth, while Blockbuster relied on store returns and late-fee revenue; the sources do not isolate these model differences as the cause of the outcome. | Media / Subscription | Business model constraint alignment (qualitative) | Netflix reported 857,000 subscribers at year-end 2002, 2.61 million at year-end 2004, and about 20 million at year-end 2010. Blockbuster projected that eliminating late fees would reduce 2005 operating income by $250 million to $300 million. | 1999-2010 | Working | Case | Press, Press, Company filing, Company filing, Company filing, Company filing |
| BS-0069 | Observational case | Google ended standalone Wave development in 2010; co-creator Lars Rasmussen described the project as ambitious and questioned its rapid, resource-heavy execution. | Technology / Collaboration tools | Adoption (reported) and usability barriers (qualitative) | Creators reported misalignment between their needs and mass-market learning costs; early active usage was low relative to invites (reported). | 2009-2012 | Working | Case | Interview, Reference |
| BS-0070 | Observational case | Quibi launched as commute-oriented short-form video during the 2020 collapse in commuting, reported low trial conversion, and shut down about six months later; the sources do not isolate a single cause. | Media / Failures | Trial-to-paid conversion; subscriber counts (reported) | Trial-to-paid conversion reported ~8% for early cohorts (Sensor Tower estimate); shutdown announced ~6 months post-launch. | Apr-Oct 2020 | Working | Case | Press, Press, Press |
| BS-0071 | Observational case | Meditation-app studies report substantial early attrition and low retention; effort, delayed rewards, fit, and scaffolding are hypotheses for this pattern rather than established causes. | Health / Digital therapeutics | Attrition and retention rates | Meta-analytic attrition ~25% (higher in larger studies); median 30-day retention for mindfulness apps reported ~4.7% (app analytics). | 30 days and longer; study-dependent | Working | Case | Meta-analysis, Study |
| BS-0072 | Observational case | Digital health studies report substantial early dropout and abandonment; a scoping review identified reported reasons including technical and functional issues, privacy concerns, poor user experience, content and features, time and financial costs, and changing user needs. | Health / Digital products | Dropout and abandonment rates | Health app dropout reported ~43%; median abandonment over time can exceed 70% (study-dependent). | First weeks to ~100 days (study-dependent) | Working | Case | Study |
| BS-0073 | Comparative test | Simplifying HIV treatment behaviors (single-tablet regimens; long-acting injectables) improves adherence and clinical outcomes compared to higher-burden regimens. | Healthcare / Adherence | Adherence and viral suppression; discontinuation | Meta-analysis: discontinuation 36.3% (single-tablet) vs 48.8% (multi-tablet); ~21% higher odds of undetectable viral load (reported). | Meta-analysis (study periods vary) | High | Case | Meta-analysis, Meta-analysis, Report |
| BS-0074 | Observational case | Blue Apron cohorts showed steep reported retention declines over six months; fit with weekly planning, cooking, and delivery management is a hypothesis for meal-kit churn, not an isolated cause. | Consumer subscription / Food | Customer retention over time | Blue Apron reported ~50% continuation after two weeks and ~10% after six months (press reporting; varies by cohort). | First 6 months | Working | Case | Press, Press |
| BS-0075 | Observational case | Waze paired low-friction micro-contributions and rewards with large reported growth in crowdsourced traffic data; available case sources do not isolate effects on adoption or navigation outcomes. | Technology / Navigation | User growth and contribution volume (reported) | At acquisition: ~50M users (reported); incident reporting and map edits at large scale (reported). | 2009-2013 and beyond | Working | Case | Press, Case write-up, Press |
| BS-0076 | Observational case | In two company moves to open-plan offices, face-to-face interaction fell sharply while electronic messaging rose; the before-and-after design does not isolate noise or interruption as the cause. | Workplace design | Face-to-face interaction time; email/IM volume | Face-to-face interaction decreased ~70%; email increased ~56%; IM increased ~67% after open office adoption (field study). | Before/after move to open plan (Fortune 500 HQ) | High | Case | Journal article, Review |
| BS-0077 | Comparative test | Responsible beverage service (RBS) training reduces over-service and alcohol-related harms by targeting the gatekeeper behavior that can change in the moment. | Public health / Alcohol harms | Crash and injury outcomes; intoxication measures | Oregon server-training mandate associated with a 23% reduction in fatal single-vehicle nighttime crashes; community reviews report reduced intoxicated driving and related harms. | 1986-1994 (Oregon); multi-study reviews | High | Case | Systematic review, Study |
| BS-0078 | Observational case | In a company-authored account, Proposify reported low completion of its old onboarding and, one month after a guided tutorial launched, a slight increase in trial-to-paid conversion plus associations between tutorial completion, proposal sending, and payment; no denominators, base rates, or causal comparison were reported. | SaaS / Sales enablement | Onboarding completion, proposal sending, and trial-to-paid conversion (company-reported) | Not estimable from the published account; sample counts, base and post rates, uncertainty, and a defined calculation were not reported. | Old flow had been in place for over one year, but the analyzed baseline window was not reported; post-launch observation was about one month | Working | Case | Company-reported, Company post |
| BS-0079 | Observational case | M-PESA’s public pilot accounts support candidate-use and operating-support hypotheses; they do not establish a representative paid first-use or repeat-opportunity rate. | Financial services / Public-source teaching | Participant-reported pilot observations and development history | No complete opportunity-to-completion rate is recoverable from the reviewed accounts. | Pilot began 11 October 2005 and officially ended 1 May 2006; source publication dates differ from event dates | Working | Case | Participant-authored case, Company-published research report, Company retrospective |
| BS-0080 | Observational case | Instagram’s early public history supports a qualified reconstruction of product focus and problem selection; it supplies no isolated causal estimate for the pivot. | Consumer technology / Product strategy | Qualitative product history and founder-reported user count | Nearly 4 million users reported in May 2011; no established active-user, completion or retention rate | 2010 product decision; founder talk on 11 May 2011; later engineering account in October 2015 | Working | Case | Founder talk, Transcript of the same talk, Contemporaneous product observation, Founder retrospective |
| BS-0081 | Observational case | The NAO’s 2019 Verify audit identifies gaps between reported identity-registration success and the user’s complete government-service journey. | Public digital services / Identity assurance | Reported Verify registration success and the boundaries of its denominator and endpoint | 48% reported single-attempt sign-up success in February 2019 versus an earlier 90% projection; not an end-to-end service-completion rate or a treatment effect | Performance through February 2019; NAO report published 5 March 2019 | Working | None | Independent government audit, Primary audit report, Summary of the same audit |
| BS-0082 | Comparative test | Wikimedia’s Growth experiment found improved first-edit activation; the reported increase in retained editors was inferred through activation rather than directly detected. | New accounts on Arabic, Vietnamese, Czech, and Korean Wikipedias | First Article or Article Talk edit within 24 hours; constructive first edit unreverted within 48 hours; another edit on a different day in the following two weeks after activation | Activation improved; no retention change was directly detected. No feature-specific effect is isolated here. | Accounts registered November 21, 2019 to May 14, 2020; November 2020 analysis | Working | None | Original experiment report |
| BS-0083 | Comparative test | Six California outreach experiments found no detected increase in tax filing or EITC claiming from the tested letters and text messages. | California households sampled for outreach; six partly overlapping trials | Administrative household-level filing and credit-claim outcomes; website engagement is an intermediate measure | No detected increase in the primary filing or claiming outcomes; no pooled numerical effect asserted here | Spring 2018 and spring 2019, addressing tax years 2017 and 2018 | Working | None | Peer-reviewed study, Author working paper with methods and appendix |
How to add a row #
- Add an entry to
/_data/evidence_ledger.yml. - Assign one evidence class from the Editorial Policy.
- Add the canonical case path to
case_bindingswhen a public case cites the record. - Use
{% include evidence-ref.html id="BS-XXXX" %}next to the claim on the relevant page. - Keep denominators explicit and attach a named calculation or source receipt for each quantitative case.
The YAML ledger is the only public source of evidence rows. Do not copy ledger rows into a second table or page.