# \#model-checking

**URL:** https://discourse.pymc.io/tag/model-checking/98.md

[Latest](https://discourse.pymc.io/latest.md) · [Categories](https://discourse.pymc.io/categories.md) · [Tags](https://discourse.pymc.io/tags.md)

---

## [Sampling not finishing in Databricks? Try disabiling the progress bar or any widgets](https://discourse.pymc.io/t/sampling-not-finishing-in-databricks-try-disabiling-the-progress-bar-or-any-widgets/17282)

<div class="topic-metadata">

**Author:** [@brontidon](https://discourse.pymc.io/u/brontidon)\
**Replies:** 3\
**Last updated:** [September 15, 2025, 10:03pm UTC](https://discourse.pymc.io/t/sampling-not-finishing-in-databricks-try-disabiling-the-progress-bar-or-any-widgets/17282 "2025-09-15T22:03:56Z")

</div>

Hey everyone: just a heads up-last week I was curious why some simpler models would not finish sampling in Databricks when I came up on some discourse on the Databricks forums(Notebook cell gets hung up but code complete…

---

## [Checking Model Fit: World of Warcraft Item Levels](https://discourse.pymc.io/t/checking-model-fit-world-of-warcraft-item-levels/16658)

<div class="topic-metadata">

**Author:** [@Delro](https://discourse.pymc.io/u/Delro)\
**Replies:** 3\
**Last updated:** [March 10, 2025, 4:29am UTC](https://discourse.pymc.io/t/checking-model-fit-world-of-warcraft-item-levels/16658 "2025-03-10T04:29:46Z")

</div>

I’m new to using PYMC/Bayesian modeling, so as a little test drive, I decided to record the item levels of players in world of warcraft before and after the start of this latest season. I was interested in seeing how the…

---

## [Blog: The right way to do predictive checks with observation-level random effects](https://discourse.pymc.io/t/blog-the-right-way-to-do-predictive-checks-with-observation-level-random-effects/16131)

<div class="topic-metadata">

**Author:** [@ErikRingen](https://discourse.pymc.io/u/ErikRingen)\
**Replies:** 2\
**Last updated:** [November 21, 2024, 11:15am UTC](https://discourse.pymc.io/t/blog-the-right-way-to-do-predictive-checks-with-observation-level-random-effects/16131 "2024-11-21T11:15:01Z")

</div>

I’ve released a short blog about performing posterior predictive checks for models with observation-level random effects (OLREs) (e.g., for over-dispersed counts). This has come up a few times for me while consulting, so…

---

## [Issue with az.plot\_ppc Showing a Single Straight Line in Non-linear Differential Equations](https://discourse.pymc.io/t/issue-with-az-plot-ppc-showing-a-single-straight-line-in-non-linear-differential-equations/14927)

<div class="topic-metadata">

**Author:** [@Dimlitter](https://discourse.pymc.io/u/Dimlitter)\
**Replies:** 3\
**Last updated:** [August 18, 2024, 2:37pm UTC](https://discourse.pymc.io/t/issue-with-az-plot-ppc-showing-a-single-straight-line-in-non-linear-differential-equations/14927 "2024-08-18T14:37:58Z")

</div>

Hi everyone, I’m currently working on validating the posterior distribution of a SEIRS model using the az.plot\_ppc function from the ArviZ library. However, when I generate the posterior predictive checks, the plot only…

---

## [Vectorisation of BART for multidimension hierarchical data](https://discourse.pymc.io/t/vectorisation-of-bart-for-multidimension-hierarchical-data/14351)

<div class="topic-metadata">

**Author:** [@hsteptoe](https://discourse.pymc.io/u/hsteptoe)\
**Replies:** 2\
**Last updated:** [July 3, 2024, 10:03pm UTC](https://discourse.pymc.io/t/vectorisation-of-bart-for-multidimension-hierarchical-data/14351 "2024-07-03T22:03:08Z")

</div>

TL,DR: I’m trying to vectorise a BART model to be hierarchical, but I can’t get the coordinates/dimensions working I have data that describes how a series of features give a variable response. The features space is larg…

---

## [What is the suitable regression model for proportions data with 0 and 1 values?](https://discourse.pymc.io/t/what-is-the-suitable-regression-model-for-proportions-data-with-0-and-1-values/14598)

<div class="topic-metadata">

**Author:** [@Mustapha\_Momoh](https://discourse.pymc.io/u/Mustapha_Momoh)\
**Replies:** 3\
**Last updated:** [June 13, 2024, 11:06am UTC](https://discourse.pymc.io/t/what-is-the-suitable-regression-model-for-proportions-data-with-0-and-1-values/14598 "2024-06-13T11:06:20Z")

</div>

Hello PyMC Community, I am analyzing a dataset for Regression Discontinuity Design where the dependent variable, y, represents the fraction of students at each unique score who rated their experience of taking an exam r…

---

## [Bayesian Regression: Inconsistent Prior Predictive Checks](https://discourse.pymc.io/t/bayesian-regression-inconsistent-prior-predictive-checks/13035)

<div class="topic-metadata">

**Author:** [@J\_V](https://discourse.pymc.io/u/J_V)\
**Replies:** 12\
**Last updated:** [October 9, 2023, 9:20am UTC](https://discourse.pymc.io/t/bayesian-regression-inconsistent-prior-predictive-checks/13035 "2023-10-09T09:20:49Z")

</div>

I’m working on a Bayesian regression problem using PyMC and have encountered an issue with my prior predictive checks. I have some observed x, y data points and have constructed a Bayesian regression model with informati…

---

## [How to interpret posterior/prior predictive checks](https://discourse.pymc.io/t/how-to-interpret-posterior-prior-predictive-checks/12973)

<div class="topic-metadata">

**Author:** [@J\_V](https://discourse.pymc.io/u/J_V)\
**Replies:** 2\
**Last updated:** [September 25, 2023, 12:19pm UTC](https://discourse.pymc.io/t/how-to-interpret-posterior-prior-predictive-checks/12973 "2023-09-25T12:19:13Z")

</div>

Hello PyMC community! I’ve been diligently studying the documentation and following various books that leverage PyMC in their examples. Now, as I’ve ventured into creating my first model, I find myself facing some uncer…

---

## [Unsure how to proceed with prior and posterior predictive checking for Bayesian multiple logistic regression](https://discourse.pymc.io/t/unsure-how-to-proceed-with-prior-and-posterior-predictive-checking-for-bayesian-multiple-logistic-regression/12437)

<div class="topic-metadata">

**Author:** [@Thomas](https://discourse.pymc.io/u/Thomas)\
**Replies:** 6\
**Last updated:** [July 6, 2023, 6:24pm UTC](https://discourse.pymc.io/t/unsure-how-to-proceed-with-prior-and-posterior-predictive-checking-for-bayesian-multiple-logistic-regression/12437 "2023-07-06T18:24:01Z")

</div>

Hi everyone, Apologies if this question was answered previously - if so, I would appreciate any further reading and references! I did a thorough search both here and elsewhere, and I believe there is scarce information …

---

## [Can MCMC Sampling be used in lieu of Cross Validation for model evaluation?](https://discourse.pymc.io/t/can-mcmc-sampling-be-used-in-lieu-of-cross-validation-for-model-evaluation/12026)

<div class="topic-metadata">

**Author:** [@Samridhi\_Verma](https://discourse.pymc.io/u/Samridhi_Verma)\
**Replies:** 1\
**Last updated:** [May 3, 2023, 2:19pm UTC](https://discourse.pymc.io/t/can-mcmc-sampling-be-used-in-lieu-of-cross-validation-for-model-evaluation/12026 "2023-05-03T14:19:51Z")

</div>

Currently I’m building a marketing mix model using Pymc module. My supervisor has raised a technical pymc related question and I am looking for concrete answers. The question is - “Usual practice in ML is to split data i…

---

## [Basic population and group level estimation example: suggestions for improvements?](https://discourse.pymc.io/t/basic-population-and-group-level-estimation-example-suggestions-for-improvements/11808)

<div class="topic-metadata">

**Author:** [@hsteptoe](https://discourse.pymc.io/u/hsteptoe)\
**Replies:** 6\
**Last updated:** [April 8, 2023, 12:59am UTC](https://discourse.pymc.io/t/basic-population-and-group-level-estimation-example-suggestions-for-improvements/11808 "2023-04-08T00:59:34Z")

</div>

I’m trying to build a basic model to test my understanding of estimating population and group level effects . I’m leaning on existing examples, such as Rugby Analytics and Multilevel Modelling but want to try an even si…

---

## [How to use the posterior predictive distribution for checking a model from PyMC](https://discourse.pymc.io/t/how-to-use-the-posterior-predictive-distribution-for-checking-a-model-from-pymc/11593)

<div class="topic-metadata">

**Author:** [@Andre](https://discourse.pymc.io/u/Andre)\
**Replies:** 10\
**Last updated:** [March 14, 2023, 6:49pm UTC](https://discourse.pymc.io/t/how-to-use-the-posterior-predictive-distribution-for-checking-a-model-from-pymc/11593 "2023-03-14T18:49:29Z")

</div>

I’m a little confused because this question is not of great scientific interest and rather relates to a lack of knowledge on my part. I am trying to understand how to use a posterior predictive check (PPC) after buildin…