Johnny Felt's Avatar

Johnny Felt

@jfeltphd.bsky.social

Quantitative methodologist interested in Bayesian and frequentist approaches to longitudinal data analysis, causal inference, and measurement. Assistant Research Professor in the Center for Healthy Aging at Penn State. UC Merced Quant Psych Alum.

877 Followers  |  445 Following  |  69 Posts  |  Joined: 22.09.2023  |  2.0511

Latest posts by jfeltphd.bsky.social on Bluesky

Oh I see! Then I also agree lol

31.07.2025 00:16 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Which is why the causal inference we work with is probabilistic and not deterministic

31.07.2025 00:00 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

I’m with @solomonkurz.bsky.social . Is this how the field is looking at causal inference? The causal inference class I took in grad school and the ones I teach focus on how we typically only have INUS conditions.

30.07.2025 23:58 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0

Take a look at our new pre print for different approach on how to calculate the dynamic range of diurnal cortisol, led by the talented @kvanbogart.bsky.social

26.07.2025 17:59 β€” πŸ‘ 1    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
OSF

New preprint!

Interested in examining HPA axis regulation or allostatic load? We present three approaches to computing the dynamic range of diurnal cortisol β€” with advantages, limitations, and examples with R code for each approach.

osf.io/preprints/os...

25.07.2025 15:15 β€” πŸ‘ 7    πŸ” 5    πŸ’¬ 1    πŸ“Œ 1

All this! I just did a causal inference workshop at Penn State and I started off with β€œstats can’t save you here. Causal inference is a qualitative inference given the data collected and the design of your study.” It was very Shadish, Cook, and Campbell heavy with a dash of DAGs

23.07.2025 18:56 β€” πŸ‘ 3    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

This book was so good! Have you read jonathan strange and mr norrell yet?

19.07.2025 14:24 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

The tabachnick and Fidell book, analyzing experiments using ANOVA. has a nice section on a priori contrast for one way and factorial ANOVAs. They even include a table at the end for different contrast based on the number of groups you have. Linda collins MOST book is a good one too

02.07.2025 13:57 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

If MCAR, I’ll just randomly impute 1s and 0s so I don’t lose power

23.06.2025 18:07 β€” πŸ‘ 3    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

I will be damned if I allow a bunch of Confederate-waving January 6th apologists give the American people a lecture on flag waving.

There is ZERO reason to enter an argument about patriotism with people who still worship traitors to America 150+ years later.

They. Are. Breaking. The. Law.

11.06.2025 01:21 β€” πŸ‘ 104958    πŸ” 22575    πŸ’¬ 1441    πŸ“Œ 674

Oh absolutely. Unfortunately it means you’ll have to double check these errors in lme4 before determining if they are erroneous though

19.05.2025 14:38 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Another thing to request, particularly when using lme4 or nlme in R, is the confidence intervals. If you just do a summary on the model object, you won’t actually know if your model has converged, particularly in the random effects. Asking for confint (in lme4) or intervals(in nlme) will check this

17.05.2025 23:13 β€” πŸ‘ 6    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

As a Sacramento kings fan, I am a fan of anyone that is a thorn in the Lakers side. Go Celtics!

20.04.2025 17:23 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Post image

πŸ“… Save the date – May 14 @ 1:30 p.m.! Join us for our BERD Workshop Webinar: β€œCausal Inferences for Experimental and Quasi-Experimental Designs” |βœ… Reserve your spot: bit.ly/4jB2EIU

18.04.2025 19:34 β€” πŸ‘ 4    πŸ” 1    πŸ’¬ 0    πŸ“Œ 1

You can follow along with members of our Early Career Editorial Board through this starter pack: go.bsky.app/7wdxZUn

09.01.2025 20:21 β€” πŸ‘ 9    πŸ” 5    πŸ’¬ 1    πŸ“Œ 1

Have you been telling participants to β€œgit gud” in your studies?

08.04.2025 22:08 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Wow, this is an impressive three to have in one talk!

08.04.2025 22:05 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

I once heard someone say that β€œthey didn’t need to randomize because the data were all collected so close in time to each other”

24.03.2025 11:47 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Preview
Rates of Population-Level Child Sexual Abuse After a Community-Wide Preventive Intervention This study tests whether a coordinated, community-wide preventive intervention could significantly reduce population-level incidence rates of child sexual abuse.

Check out this new one from JAMA Pediatrics that I did the analyses for

jamanetwork.com/journals/jam...

We used Synthetic Control Method to evaluate the effectiveness of a coordinated county-level child sexual abuse prevention intervention program

03.03.2025 23:59 β€” πŸ‘ 6    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Definitely this paper. It is written so clearly without a lot (or any equations). It helped me also see that the whole DAGs framework also fits with the threats to validity and the Rubin’s causal framework

28.02.2025 15:58 β€” πŸ‘ 3    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

That is a really clever poster design

22.02.2025 23:52 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

I agree with all of this. Outliers are really individuals in your sample that come from a different population than you intended to collect, not necessarily extreme values.

20.02.2025 00:56 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

The BSAM @psychosommed.bsky.social Early Career Editorial Board provides a pathway for outstanding early career researchers around the globe to gain experience in reviewing and editorial functions. Apply by April 15. Please share with colleagues and rebleat!
journals.lww.com/bsam/Documen...

19.02.2025 19:16 β€” πŸ‘ 7    πŸ” 12    πŸ’¬ 0    πŸ“Œ 2

Will shadish had a great paper on this where participants were randomized to choose their condition or to be randomly assigned to condition www.statpower.net/Content/MLRM...

19.02.2025 00:16 β€” πŸ‘ 5    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Interesting. I wonder if these findings generalize across methods for establishing childhood adversity? Lots of work on how prospective and objective measures of child maltreatment (to biological measures) are related to different outcomes than retrospective self-report (to psych measures)

10.02.2025 19:44 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

EMA/Daily Diary researchers!

Do you have a dataset with momentary or daily loneliness among adults 18+? @kvanbogart.bsky.social is seeking datasets to support a coordinated data analysis

Email Karina.vanbogart@northwestern.edu with a brief description of your dataset to be considered! #psychscisky

31.01.2025 20:14 β€” πŸ‘ 49    πŸ” 38    πŸ’¬ 5    πŸ“Œ 2

Yes, this administration is dangerous and cruel, but they are also shockingly dim and incompetent.

Opportunities are everywhere.

Make everything as hard as possible. Resist every demand. Refuse entry without a warrant. Don’t take the buyout. Their problem solving skills are πŸ“‰

30.01.2025 02:35 β€” πŸ‘ 191349    πŸ” 41992    πŸ’¬ 3709    πŸ“Œ 1957

That’s a great question. I haven’t seen anything published on that. I only have a single anecdote with an adult male around 59 years old. when I was collecting my dissertation data, the father of one of my RAs wanted to try it and it worked despite him knowing the goal and undergrad confederates

25.01.2025 14:18 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Preview
The Resurrection of Doseone After decades of heartbreak, loss, and reinvention, the prolific artist returns to his roots with β€œAll Portrait, No Chorus”—a fearless reminder of hip-hop's boundless potential.

I had no idea that I would get a burst of motivation after reading this @bandcamp.com article about @doseone.bsky.social , but here I am sciencing on a Saturday daily.bandcamp.com/features/dos...

18.01.2025 18:39 β€” πŸ‘ 17    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0
Preview
All Portrait, No Chorus, by doseone & Steel Tipped Dove 14 track album

Wow, I was not expecting a release from @doseone.bsky.social! This album is a incredible

doseone.bandcamp.com/album/all-po...

11.01.2025 16:42 β€” πŸ‘ 4    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

@jfeltphd is following 19 prominent accounts