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Andrew Mercer

@awmercer

Principal methodologist at Pew Research Center. He/him

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Latest posts by Andrew Mercer @awmercer

To each their own I suppose.

07.03.2026 03:14 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Watching S1E1 of The Pitt. It’s gotta get better right? Is this just the usual crappy pilot after which they bring in a showrunner that knows what they’re doing?

07.03.2026 02:09 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

One of those legendary pieces of online statistical lore that everyone needs be aware of.

04.03.2026 13:56 πŸ‘ 31 πŸ” 3 πŸ’¬ 5 πŸ“Œ 0
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Royal Statistical Society Publications Surveys are well known to contain response errors of different types, including acquiescence, social desirability, common method variance and random error simultaneously. Nevertheless, a single error...

You might check out this paper by Cernat and @daob.nl that seems along the lines of what you’re thinking. Not substantively but as a method for doing it.

04.03.2026 13:43 πŸ‘ 1 πŸ” 1 πŸ’¬ 1 πŸ“Œ 0

With very large numbers of n’s you don’t need randomization, and with LLM’s we can generate very large numbers of n’s, so I think all of science is solved by now. I don’t see any problems with this.

03.03.2026 23:27 πŸ‘ 96 πŸ” 18 πŸ’¬ 5 πŸ“Œ 1

Nobody can post unless they’re connected over dialup at speeds not to exceed 14.4 kbps.

03.03.2026 00:38 πŸ‘ 5 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Can. Not. Wait.

03.03.2026 00:35 πŸ‘ 8 πŸ” 0 πŸ’¬ 2 πŸ“Œ 0

If they don’t know it THAT’S 50 DKP MINUS!!!

02.03.2026 17:58 πŸ‘ 2 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Woke up and chose violence, eh?

02.03.2026 14:02 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Would pay good money for this.

02.03.2026 02:28 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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Longitudinal Measurement (Non)Invariance in Latent Constructs: Conceptual Insights, Model Specifications, and Testing Strategies Abstract. The chapter discusses the basic principles and core problems of latent variable panel modelling, with a focus on the specification of error struc

This chapter from a volume edited by Cernat might be of interest.

academic.oup.com/book/39454/c...

01.03.2026 15:30 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

This is a good question for @daob.nl. This is very much in his area of expertise. Alexandru Cernat also but I don’t think he’s on here.

01.03.2026 15:19 πŸ‘ 2 πŸ” 0 πŸ’¬ 2 πŸ“Œ 0

I see. That makes sense. As @cameronpat.bsky.social said elsewhere, I guess it depends on the estimand. Correlated measurement error is a giant morass.

01.03.2026 14:39 πŸ‘ 3 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

E.g. if people who got the treatment remember their pre status as better than it really was, modeling change as a multivariate outcome seems like it would have the same bias as if your model was post ~ pre + treatment.

01.03.2026 14:19 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

It seems like this would only be necessary if the treatment would plausibly affect the way the pre condition is reported. Although in that case, an estimand measuring change since baseline seems of limited utility (although maybe it does in context).

01.03.2026 14:12 πŸ‘ 1 πŸ” 0 πŸ’¬ 2 πŸ“Œ 0

β€œaverage monkey asks 3 questions a day" factoid actualy just statistical error. average monkey asks 0 questions per year. Curious georg, who lives in cave & asks over 10,000 each day, is an outlier adn should not have been counted

01.03.2026 02:33 πŸ‘ 286 πŸ” 63 πŸ’¬ 4 πŸ“Œ 0

lol, I wouldn’t know!

01.03.2026 04:20 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

I’m probably going to buy it, play it for about an hour, get freaked out by something creepy and never touch again. This is my standard MO for Resident Evil games.

01.03.2026 04:15 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Always

01.03.2026 03:46 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

Yeah, I really can't stress enough that AI code assistants royally fuck up statistical analyses. And they do it with absolute confidence.

28.02.2026 17:38 πŸ‘ 26 πŸ” 5 πŸ’¬ 1 πŸ“Œ 2

data.table - for when there aren’t enough brackets in your life.

27.02.2026 12:34 πŸ‘ 2 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0

I have wanted to attend since I first heard about it!

26.02.2026 16:13 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

I will be *very* interested to hear about your experience there.

26.02.2026 15:59 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Look, 1 was just a mess when it came to the gameplay.

26.02.2026 13:11 πŸ‘ 2 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
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Comparing Two Types of Online Survey Samples Pew Research Center conducted a study to compare the accuracy of six online surveys of U.S. adults – three from probability-based panels and three from opt-in sources. On average, the absolute error o...

I generally don’t presume any malfeasance. We see these kinds of results in opt-in samples for all sorts of items (e.g. see below). If you’re fielding an opt-in poll about religion because that’s what your organization cares about, these effects are just going to pop up in the results on their own.

25.02.2026 13:58 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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Survey Associate, Methodology Pew Research Center Organization Overview Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping America and the world. It conducts publi...

Exciting news! We just posted an opening for a Survey Associate on @pewresearch.org's Methods team! This is an amazing opportunity for someone relatively early in their career to join what is, IMO, the most fun methods team in the business. Full description at the link below.

24.02.2026 21:16 πŸ‘ 34 πŸ” 42 πŸ’¬ 1 πŸ“Œ 2

I think it’s less selection and more measurement error among low quality respondents. A mix of yeasaying and random/haphazard responding which will tend to overestimate relatively rare attitudes and behaviors.

25.02.2026 05:40 πŸ‘ 4 πŸ” 1 πŸ’¬ 1 πŸ“Œ 0
Online opt-in surveys also find recent religious resurgence among U.S. young adults While this analysis focuses on claims of religious revival among young adults in the U.K., some opt-in surveys have pointed to a similar trend in the United States.  Barna Group, a research organization serving Christian leaders, has used online opt-in survey data to make claims of rising churchgoing among young adults in the U.S. According to Barna, β€œSince 2019, both Gen Z and Millennials were the least likely generation to frequently attend church. Today, they are the most engaged.”  However, surveys from Pew Research Center using random samples show no clear evidence of a religious revival among young adults. Nor is there clear evidence of religious revival in two other surveys based on random samples conducted by other organizations: the General Social Survey and the American Time Use Survey.

Online opt-in surveys also find recent religious resurgence among U.S. young adults While this analysis focuses on claims of religious revival among young adults in the U.K., some opt-in surveys have pointed to a similar trend in the United States. Barna Group, a research organization serving Christian leaders, has used online opt-in survey data to make claims of rising churchgoing among young adults in the U.S. According to Barna, β€œSince 2019, both Gen Z and Millennials were the least likely generation to frequently attend church. Today, they are the most engaged.” However, surveys from Pew Research Center using random samples show no clear evidence of a religious revival among young adults. Nor is there clear evidence of religious revival in two other surveys based on random samples conducted by other organizations: the General Social Survey and the American Time Use Survey.

Is there a revival of churchgoing among US young adults? According to
Opt-in online polls: Yes
Surveys using random samples of the population: No
https://www.pewresearch.org/short-reads/2026/01/23/has-there-been-a-christian-revival-among-young-adults-in-the-uk-recent-surveys-may-be-misleading/

25.02.2026 05:27 πŸ‘ 266 πŸ” 61 πŸ’¬ 10 πŸ“Œ 4
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GitHub - frankiethull/iltm: iLTM: Integrated Large Tabular Model with R iLTM: Integrated Large Tabular Model with R. Contribute to frankiethull/iltm development by creating an account on GitHub.

github.com/frankiethull...

24.02.2026 22:53 πŸ‘ 6 πŸ” 2 πŸ’¬ 0 πŸ“Œ 0

So it’s not this particular position, but we do have a former intern who went on to be a finalist on Survivor.

24.02.2026 23:53 πŸ‘ 2 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0