# New PyMCon Talk Released: Missing Value Imputation with Item Response Theory by Allen Downey & Ricardo Vieira

**URL:** <https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403>\
**Category:** PyMCon Web Series\
**Created:** [December 2, 2023, 5:35pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403 "2023-12-02T17:35:52Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![purna135](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/purna135/32/4895_2.png) [@purna135](https://discourse.pymc.io/u/purna135)\
**Post date:** [December 2, 2023, 5:35pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/1 "2023-12-02T17:35:52Z")

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[![](https://img.youtube.com/vi/uyznG61myy0/maxresdefault.jpg "PyMCon Web Series -Missing Value Imputation with Item Response Theory -Allen Downey & Ricardo Vieira") ](https://www.youtube.com/watch?v=uyznG61myy0)

Hi Everyone 🙋‍♂️

Come to our next PyMCon Web Series! We’re talking about ‘ **Missing Value Imputation with Item Response Theory** ’

**Speakers:**

1. **[Allen Downey](https://www.allendowney.com/)**, Professor Emeritus at [Olin College](http://www.olin.edu/), and the author of _Think Python_ , _Think Bayes_ , _Think Stats_ and other books related to computer science and data science.
2. **[Ricardo Vieira](https://ricardov94.github.io/posts/)**, PyMC developer and data scientist at [PyMC Labs](https://www.pymc-labs.com/)

**Event type:** Recorded Talk with Live Q&A  
**Q&A Date/Time:** 2023-12-15T15:00:00Z([subscribe here](https://dashboard.mailerlite.com/forms/241188/73241617305175542/share)for email updates)  
**Register for Q&A:** [Meetup event](https://www.meetup.com/pymc-online-meetup/events/297705345/) (to get the Zoom link)  
**Website:** [PyMCon Events · PyMCon Web Series](https://pymcon.com/events/)

## Details:

In many large surveys, not every respondent is asked every question, and not every respondent answers the questions they are asked. So, how can we compare people who answer different sets of questions? One solution is to use item response theory (IRT) to impute missing responses—and nothing pairs better with IRT than Bayesian methods!

In this talk, we will report the results of a friendly competition—a bake-off—between two approaches to this problem: one using grid algorithms and a simplified model, the other using PyMC and a more detailed model. We’ll discuss the implementations, compare the results, and outline their pros and cons.

## **Content:**

**Async Talk:** [https://www.youtube.com/watch?v=uyznG61myy0](https://www.youtube.com/watch?v=uyznG61myy0)  
**Interview video:** [https://www.youtube.com/watch?v=rvIStfmP1NU](https://www.youtube.com/watch?v=rvIStfmP1NU)  
**Slides:** [Bayesian Bake-Off: Grids, MCMC, and IRT - Google Slides](https://tinyurl.com/bbo1123)

## Event Format:

Like other PyMCon events, this one features an asynchronous component along with a synchronous Q&A session. **Stay tuned for the prerecorded talk;** we will be sharing it soon.

There will be a live Q&A on December 15, 2023, at 7:00 pm PT. Register for the event and bring all your doubts to discuss there.

📌 Here is the link:

> **[\[PyMCon\] Missing Value Imputation with Item Response Theory - Q&A, Fri,...](https://www.meetup.com/pymc-online-meetup/events/297705345/)**
>
> 🎙️ \*\*Speaker: Allen Downey\\, Ricardo Vieira \\| ⏰ Time: 3 pm UTC / 7 am PT / 10 am ET / 4 pm Berlin\*\*
> 
> In many large surveys, not every respondent is asked every question,

### About the Speaker:

1. **[Allen Downey](https://www.allendowney.com/)**  
Allen is a curriculum designer at [Brilliant](https://brilliant.org/) and Professor Emeritus at [Olin College](http://www.olin.edu/), and the author of _Think Python_, _Think Bayes_, _Think Stats_ and other books related to computer science and data science.  
He writes a blog about Bayesian statistics and related topics called _[Probably Overthinking It](https://www.allendowney.com/blog/)_. And he is working on a book, also called _Probably Overthinking It_, that will be published by University of Chicago Press in 2023. If you would like to get an occasional update about the book, please [join my mailing list](http://eepurl.com/h0nfbX).  
Dr. Mahmood is a neuroscientist with a PhD from Brandeis University, where he investigated the neural coordination of taste. His research, initially using electrophysiology to probe brain region interactions, hints at a complex network processing flavors. His forthcoming studies aim to unravel this network further, exploring the directional flow of neural information and the impact of feedback mechanisms in taste perception.

2. **Ricardo Vieira**  
Ricardo Vieira is a PyMC developer and data scientist at PyMC Labs. He spent several years teaching himself Statistics and Computer Science at the expense of his official degrees in Psychology and Neuroscience.

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**Author:** ![purna135](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/purna135/32/4895_2.png) [@purna135](https://discourse.pymc.io/u/purna135)\
**Post date:** [December 8, 2023, 10:06pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/2 "2023-12-08T22:06:54Z")

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The full interview with Allen and Ricardo is now available on our YouTube channel, where they share insights into their statistical and PyMC journeys, along with some invaluable advice. 🚀

💡 Check out the interview now, and stay tuned for their asynchronous talk tomorrow.

[![](https://img.youtube.com/vi/rvIStfmP1NU/maxresdefault.jpg "PyMCon Web Series - Meet Allen Downey & Ricardo Vieira") ](https://www.youtube.com/watch?v=rvIStfmP1NU)

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**Author:** ![purna135](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/purna135/32/4895_2.png) [@purna135](https://discourse.pymc.io/u/purna135)\
**Post date:** [December 10, 2023, 3:25pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/3 "2023-12-10T15:25:18Z")

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The Async talk and slides for this PyMCon event are now live on our YouTube channel!

Watch the Async Talk Now:

[![](https://img.youtube.com/vi/uyznG61myy0/maxresdefault.jpg "PyMCon Web Series -Missing Value Imputation with Item Response Theory -Allen Downey & Ricardo Vieira") ](https://www.youtube.com/watch?v=uyznG61myy0)

Explore the Slides:

> **[Google Slides](https://docs.google.com/presentation/d/e/2PACX-1vTecz_3OA37EGQrrbfVo-OtkenSdw6E6PNAtAphcZL6vMeMbnk2ihse_0_SQxxOldRi9eG_JxXtkgoq/pub)**
>
> This Slide is private

In case you haven’t registered for the Q&A session yet, do RSVP now to get the Zoom link: 👇

> **[\[PyMCon\] Missing Value Imputation with Item Response Theory - Q&A, Fri,...](https://www.meetup.com/pymc-online-meetup/events/297705345/)**
>
> 🎙️ \*\*Speaker: Allen Downey\\, Ricardo Vieira \\| ⏰ Time: 3 pm UTC / 7 am PT / 10 am ET / 4 pm Berlin\*\*
> 
> In many large surveys, not every respondent is asked every question,

Save the date, watch the talk, and come prepared with your questions on December 15th! Let’s make it an insightful and engaging session!

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**Author:** ![foabodo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/foabodo/32/7703_2.png) [@foabodo](https://discourse.pymc.io/u/foabodo)\
**Post date:** [December 15, 2023, 3:09pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/4 "2023-12-15T15:09:45Z")

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Question for the 12/15/2023 Q&A: I’d like to know your opinion about the feasibility of the following scenario. Imagine we have 100 students with test scores from Physics I, Physics II, and Nuclear Physics. We also have some demographic data. And 400 students with test scores from Physics I and Physics II. I want to predict the Nuclear Physics test scores for the 400 students using the methods presented in the async talk. Am I asking too much?

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**Author:** ![RavinKumar](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/ravinkumar/32/958_2.png) [@RavinKumar](https://discourse.pymc.io/u/RavinKumar)\
**Post date:** [December 15, 2023, 3:27pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/5 "2023-12-15T15:27:42Z")

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This was the second question in the chat

> I’m trying to predict the survival of ropes and I can measure things such as the force applied on the rope and time the rope is in service. However, one of the things that determines the life of the rope would be abrasions which I can’t measure. Can I input that missing information into a model or is that too much

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**Author:** ![foabodo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/foabodo/32/7703_2.png) [@foabodo](https://discourse.pymc.io/u/foabodo)\
**Post date:** [December 15, 2023, 6:42pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/6 "2023-12-15T18:42:19Z")

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Is anyone aware of public data sets that are well suited for use in exploring probabilistic IRT?

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**Author:** ![purna135](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/purna135/32/4895_2.png) [@purna135](https://discourse.pymc.io/u/purna135)\
**Post date:** [December 20, 2023, 6:48pm UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/7 "2023-12-20T18:48:54Z")

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If you missed our live Q&A session the recording is now available on YouTube:

[![](https://img.youtube.com/vi/mNbPpTDfaws/maxresdefault.jpg "PyMCon Web Series - Missing Value Imputation with Item Response Theory - Q&A | Allen & Ricardo") ](https://www.youtube.com/watch?v=mNbPpTDfaws)

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**Author:** ![foabodo](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/foabodo/32/7703_2.png) [@foabodo](https://discourse.pymc.io/u/foabodo)\
**Post date:** [February 15, 2024, 2:05am UTC](https://discourse.pymc.io/t/new-pymcon-talk-released-missing-value-imputation-with-item-response-theory-by-allen-downey-ricardo-vieira/13403/8 "2024-02-15T02:05:25Z")

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I found a near-ideal dataset in [this paper](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0195297)! Essay scoring by multiple graders per student with many tens of thousands of data points.