From 8b5335610086e41c50accab705bc1e4c5e7d4a69 Mon Sep 17 00:00:00 2001
From: Adam Howes <xwg3@cdc.gov>
Date: Wed, 16 Oct 2024 17:31:41 +0100
Subject: [PATCH] Issue #391: Add `priorsense` to FAQ (#392)

---
 DESCRIPTION              |  3 ++-
 vignettes/faq.Rmd        | 10 ++++++++++
 vignettes/references.bib | 21 ++++++++++++++++-----
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index 5cf4bf151..e342ed8b2 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -50,7 +50,8 @@ Suggests:
     tidybayes,
     modelr,
     patchwork,
-    cmdstanr
+    cmdstanr,
+    priorsense
 Additional_repositories:
     https://stan-dev.r-universe.dev
 Config/Needs/website:
diff --git a/vignettes/faq.Rmd b/vignettes/faq.Rmd
index 869c9b8d9..e0df64174 100644
--- a/vignettes/faq.Rmd
+++ b/vignettes/faq.Rmd
@@ -158,6 +158,16 @@ quantile(pred$mean, c(0.01, 0.1, 0.25, 0.5, 0.75, 0.9, 0.99))
 quantile(pred$sd, c(0.01, 0.1, 0.25, 0.5, 0.75, 0.9, 0.99))
 ```
 
+# How can I assess how sensitive the fitted posterior distribution is to the prior distribution used?
+
+We recommend use of the [`priorsense`](https://github.com/n-kall/priorsense) R package [@kallioinen2024detecting] to check how sensitive the posterior distribution is to perturbations of the prior distribution and likelihood using power-scaling analysis:
+
+```{r}
+library(priorsense)
+powerscale_plot_dens(fit, variable = c("Intercept", "Intercept_sigma")) +
+  theme_minimal()
+```
+
 # What do the parameters in my model output correspond to?
 
 The `epidist` package uses `brms` to fit models.
diff --git a/vignettes/references.bib b/vignettes/references.bib
index 8425d35d3..d69f99724 100644
--- a/vignettes/references.bib
+++ b/vignettes/references.bib
@@ -103,9 +103,20 @@ @article{fang2016transmission
 }
 
 @misc{who_ebola_2014_2016,
-  author       = {{World Health Organization}},
-  title        = {Ebola outbreak 2014-2016 - West Africa},
-  year         = 2016,
-  url          = {https://www.who.int/emergencies/situations/ebola-outbreak-2014-2016-West-Africa},
-  note         = {Accessed: 2024-05-28}
+  author={{World Health Organization}},
+  title={Ebola outbreak 2014-2016 - West Africa},
+  year=2016,
+  url={https://www.who.int/emergencies/situations/ebola-outbreak-2014-2016-West-Africa},
+  note={Accessed: 2024-05-28}
+}
+
+@article{kallioinen2024detecting,
+  title={Detecting and diagnosing prior and likelihood sensitivity with power-scaling},
+  author={Kallioinen, Noa and Paananen, Topi and B{\"u}rkner, Paul-Christian and Vehtari, Aki},
+  journal={Statistics and Computing},
+  volume={34},
+  number={1},
+  pages={57},
+  year={2024},
+  publisher={Springer}
 }