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bbotk vs loo

A side-by-side editorial comparison of bbotk and loo — release velocity, themes, recent moves, and the top alternatives to consider.

bbotk vs loo: at a glance

Featurebbotkloo
SectorAnalyticsAnalytics
Velocity score2.52.5
Sparks · 30d00
Top themesblack-box optimization, mlr3, async execution, api deprecationbayesian, cross-validation, stan, r-stats
Last editorial update2h ago1h ago
WebsiteVisit →Visit →

What is bbotk?

bbotk is generalizing from an optimizer toolkit into an evaluation framework.

bbotk is the black-box optimization backend behind mlr3 tuning: search spaces, terminators, archives, and an async layer built on rush. Recent releases pair steady async-API buildout with removal of the deprecated arguments that preceded it. The 1.9.0 release introduced EvalInstance as a base class for OptimInstance, separating evaluating an objective from optimizing one.

Read the full bbotk trajectory →

What is loo?

loo keeps rewriting the diagnostics Bayesian modellers read off model comparison

loo computes leave-one-out cross-validation and model comparison for Bayesian models in the Stan ecosystem. Two releases in this window changed what users actually read: 2.7.0 replaced the fixed Pareto-k thresholds with sample-size-dependent ones and dropped the middle category, and 2.10.0 reshaped loo_compare's output into a data.frame with new uncertainty columns. The releases between are diagnostic robustness fixes and moment-matching corrections.

Read the full loo trajectory →

bbotk vs loo: editorial side-by-side

B
bbotk
ANALYTICS
2.5

bbotk is generalizing from an optimizer toolkit into an evaluation framework.

◆ Current state

bbotk is the black-box optimization backend behind mlr3 tuning: search spaces, terminators, archives, and an async layer built on rush. Recent releases pair steady async-API buildout with removal of the deprecated arguments that preceded it. The 1.9.0 release introduced EvalInstance as a base class for OptimInstance, separating evaluating an objective from optimizing one.

◆ Where it's heading

Two threads run through the visible history. The first is async optimization maturing: ArchiveAsync gained a full push/finish/fail vocabulary over rush tasks in 1.11.0, and 1.12.0 deleted the deprecated extra arguments it replaced. The second is dependency consolidation, with custom C hypervolume code handed to moocore and rush pinned to 1.0.0, trimming maintenance surface as the async path becomes the default.

◆ Prediction

The deprecation removals in 1.12.0 suggest the async archive API is now treated as settled; the next releases most likely build on EvalInstance rather than continuing to churn ArchiveAsync.

L
loo
ANALYTICS
2.5

loo keeps rewriting the diagnostics Bayesian modellers read off model comparison

◆ Current state

loo computes leave-one-out cross-validation and model comparison for Bayesian models in the Stan ecosystem. Two releases in this window changed what users actually read: 2.7.0 replaced the fixed Pareto-k thresholds with sample-size-dependent ones and dropped the middle category, and 2.10.0 reshaped loo_compare's output into a data.frame with new uncertainty columns. The releases between are diagnostic robustness fixes and moment-matching corrections.

◆ Where it's heading

The package is being brought in line with the current PSIS literature rather than extended with new features, and the practical effect is that the numbers practitioners quote in papers keep changing meaning. Work is increasingly delegated to posterior for shared computations, and the project has added contributor process, benchmarks and a published AI contribution policy.

◆ Prediction

Expect further work on comparison diagnostics — the p_worse and diag_* columns are new enough that their defaults and documentation will likely be revised next.

Alternatives to bbotk and loo

Other Analytics products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either bbotk or loo.

See all bbotk alternatives → · See all loo alternatives →

Recent activity from bbotk and loo

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 20d agoloopsis_smooth_tail revert and simplify arg restored
  2. 24d agobbotkDeprecated extra argument removed from ArchiveAsync methods
  3. 1mo agobbotkArchiveAsync gains full push/finish/fail task API over rush
  4. 1mo agolooloo_compare returns a data.frame with new uncertainty columns
  5. 2mo agobbotkDominance and hypervolume computation moved to moocore
  6. 4mo agobbotkmlr_test_functions adds standard optimization benchmarks
  7. 5mo agobbotkEvalInstance base class separates evaluation from optimization
  8. 7mo agolooStacking overflow fixes and posterior-based ESS
  9. 8mo agobbotkFix: conditions now work with OptimizerLocalSearch
  10. 2y agolooMore robust Pareto-k diagnostics and moment matching
  11. 2y agolooPareto-k thresholds now depend on sample size
  12. 3y agolooLOO predictive metrics and CRPS scoring functions

Frequently asked questions

What is the difference between bbotk and loo?

They serve adjacent needs but don't currently overlap on shipped themes. bbotk and loo are shipping at a similar cadence (velocity 2.5 vs 2.5, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is bbotk better than loo?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. bbotk and loo are shipping at a similar cadence (velocity 2.5 vs 2.5, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to bbotk?

Top bbotk alternatives in Analytics are ranked by recent ship velocity. Browse the "bbotk alternatives" section above for the current picks, or visit /alternatives/bbotk for the full list with editorial commentary on each.

What are the best alternatives to loo?

Top loo alternatives in Analytics are ranked by recent ship velocity. Browse the "loo alternatives" section above for the current picks, or visit /alternatives/loo for the full list with editorial commentary on each.