The acknowledgments section of the Monico Bayesian paper expresses gratitude to “Deb Nichols, John Watanabe, Sophie Nichols-Watanabe, Robert (Bob) L. Kelly, and the Dartmouth Coach for inspiring and facilitating the development of some concepts in this paper.” While that statement is accurate, there is more to the story. This Bayesian archaeology article was born, as all papers should be, surrounded by intellectual discourse, collegiality, family, friendship, great BBQ, and a poodle.

To begin, on behalf of my co-authors, I dedicate this manuscript to Deb Nichols’s memory and to her family. I met Deb when Amanda Veile, my partner, became a visiting faculty in the Department of Anthropology at Dartmouth College and our family moved to New Hampshire. Deb and her family were so kind to us; we will never forget that, and we stayed in touch through the years. Deb’s tenacity and resolve as the President of the Society for American Archaeology during the Covid-19 pandemic were crucial to its survival and advancement. Even when she was ill, her leadership exemplified courage, strength, and a commitment to serving her peers, students, and the greater good. Deb made a remarkable impact on the archaeological community and on everyone who knew her.

There are many moments with Deb that I will never forget. The following two examples reflect her legacy as a kind person and a talented intellectual. The first was the morning she graciously invited me to continue drafting my doctoral dissertation in her lab. After learning that I was working on my thesis, she wanted to ensure my access to a scholarly community as a newly minted Granite Stater. Deb was generous in her advice on grammar, vocabulary, and the science of “pitching” one’s ideas in writing while “hooking” an audience. The second reflects the long distance of her intellectual reach: It was the day she fed me BBQ and inspired the Monico paper on Bayesian statistics for archaeologists.

My motivation to organize Bayesian concepts into a paper originated in 2015 during an evening discussion at Casa Nichols-Watanabe, a cozy home surrounded by the gentle hills of the Connecticut River’s Upper Valley. This part of the world is a beautiful, forested landscape, only a short drive from the northern range of the Appalachians’ Green and White mountains. The forest is exceptional for its richness of beech, birch, and maple trees. Bob Kelly was visiting Dartmouth College’s Department of Anthropology and had presented a fantastic lecture earlier that day. Dinner to celebrate his visit was at Deb and John’s house at 6:30 PM, featuring low ‘n slow barbecued meats from the local smokehouse joint (Big Fatty’s). The restaurant’s motto claims to “put some south in your mouth,” and boy did they. Just thinking about it brings back delicious memories to my tastebuds – mmm, mmm, mmm.

While waiting for dinner, the temperature outside rose to 39˚F, balmy weather for April in northern New England. Moni, our daughter, Amanda, and I huddled around their wood-burning stove, which radiated warmth almost equal to that of our kind-hearted hosts’ friendship. A couple of hours into the soiree, Moni and Sophie, the sweet and energetic Nichols-Watanabe poodle, were running around the house, the latter seeming exhausted. According to John, tiring out Sophie was an extraordinary feat. To this day, he tells grand tales of Moni, the poodle whisperer. I was between a serving of ribs and beef brisket when I overheard Bob ask Deb if there was a straightforward paper distilling Bayesian statistics for archaeologists. Hearing this decreased my BBQ intake rate momentarily. Anyone who knows me well knows that I take my BBQ very seriously. So, this caught my attention. Bob thought that archaeologists might benefit from understanding how Bayesian inference differed from traditional statistics and, more importantly, why this approach may be necessary.

In April 2015, archaeologists were conducting Bayesian inference primarily to construct chronologies. Although technical texts were available, more accessible treatments like Buck and Meson’s “On being a good Bayesian” (June 2015) and McElreath’s “Statistical rethinking” (2016 edition) were not yet in print. So, Bob asked a reasonable question. Then, I heard Deb call my name, saying, “Erik might give you an answer.” Deb likely thought I could give some insight, knowing I was a teaching fellow in statistics at a relatively small liberal arts college near Boston at the time. In the classes, we routinely covered Bayesian statistics. Knowing Deb, though, I am sure her goal was to help an aspiring Ph.D. candidate meet a respected senior colleague like Bob Kelly. That was just Deb’s way, and I am grateful for it. So, I immediately put down my brisket plate and walked toward Deb and Bob.

After a few minutes of describing Bayesian inference, I boiled it down to two simple concepts: one, the ability to assign probabilities to our hypotheses, and two, a systematic framework to update the first concept with data. Then, I realized my thoughts would be clearer if I could organize them in writing. So, I wrote a proper answer to Bob’s question. In those days, I commuted three times a week from Lebanon, NH, to teach in Harvard’s Department of Statistics and continue my fellowship in the Department of Human Evolutionary Biology. The one-way ride started at 6 AM and ended two-and-a-half hours later. I would have time to write a rough but coherent letter. So, I began drafting the foundation for the Monico story on my way to Boston on the Dartmouth Coach while enjoying their complimentary popcorn. The story details were different, however, in the original draft.

The original characters revolved around horse race betting examples. I am not keen on horse tracks, off-track betting, or gambling. Nevertheless, I used similar examples in the classroom, where undergraduates and graduate students found them helpful. Student feedback pointed out that the Bayes’ Theorem “table work,” similar to what we present in the Monico story, seemed clearerr than the decision trees I used in class. I thought that these simple and relatable examples could help readers who wished to understand fundamental Bayesian inference. Before arriving at Boston’s South Station, I emailed Bob and Deb the letter. They were kind, thanked me for my effort, provided constructive comments, and encouraged me to develop the story further. As a result, I continued working on it.

Over time, I found other Bayesians interested in furthering this story. In April 2019, for example, I attended the Computer Applications and Quantitative Methods in Archaeology conference in Krakow, Poland. There, I met pioneer Bayesian archaeologist Prof. Caitlin Buck for lunch. We discussed our shared interests in vinification and brewing, and Bayesian archaeology, of course. The idea of using simple stories to convey complex statistical concepts was still “fermenting” in my mind, so I mentioned it. Caitlin expressed interest in collaborating. I have collaborated with Matt E. Hill for a long time. We recently developed a zooarchaeological database encompassing over 13,000 years of hunting on the Great Plains. While conducting preliminary analyses in 2020, we discussed applying Bayesian inference to these data and beyond. The idea of developing stories to explain the Bayesian concept in archaeology also piqued Matt’s interest in co-authoring this manuscript. Jesse Wolfhagen is a consummate Bayesian archaeologist. We collaborated on several projects and began talking about Bayesian zooarchaeology during our work on confidence intervals of mortality curves. Once I mentioned the idea to explain Bayesian inference in a relatable manner, he thought it would be a helpful and fun project to work on. Finally, I hope that Melissa Torquato does not regret taking my summer graduate course on Bayesian statistics in 2017. As a graduate student, Melissa’s enthusiasm for teaching, learning, and discovery has enabled her to succeed and become a budding Bayesian archaeologist. I am proud to have steered her in Bayes’ direction.

In August 2020, amidst the Covid-19 pandemic, our son Nico was born. He and Moni are the lovely inspirational muses of our lives. Two months later, one day in October, the sleep deprivation associated with our newborn must have sparked an urge to read Deb and Bob’s Bayesian letter again. The horse racing examples no longer seemed insightful for explaining Bayesian inference to archaeologists. In my reading, the most memorable and instructive texts include creative works like Neil Thompson’s “The Mysterious Fall of the Nacirema,” Kent Flannery’s “The Golden Marshalltown,” and John Shea’s “Uwasi Valley Tales.” These authors brilliantly help audiences to navigate complex concepts using stories. Employing stories as instructional devices avoids unnecessary complexities so readers can focus on and systematically understand a phenomenon.

That fall, I began drafting a story suitable for Bayesian inference featuring an archaeologist working on an ancient culture. Unfortunately, I had difficulty imagining original names for either. This creative process was not easy, given the challenges of the 2020 fall semester. Covid-19 seemed rampant. Purdue University shifted teaching modalities to online classes, and we barely left the house as cases kept rising. One upside was that we got to spend a lot of time with our children. The downside was that we spent a lockdown interacting primarily with an infant, a tween, a black lab named Leroy-Jethro, and two cats. Don’t get me wrong. I love our “angelitos” more than anything, even BBQ. But, as charming as they are, such a situation has challenges, including extreme noise levels. Put everyone together and forget about it! There is little hope for conversation, lecturing, or writing.

Nonetheless, creative luck struck one day, while we were tentatively discussing our travel plans for the upcoming holidays. This conversation was also challenging. The public health uncertainty of the time affected our decision to travel with the kids, especially with a two-month-old. Thankfully, Amanda is not only biological anthropology faculty in our academic department but also an affiliate of Purdue’s Department of Public Health. We carefully monitored the rapidly evolving Covid-19 science, infection data, and policies. Thus, not only does she enjoy my BBQ, she is also an ideal partner when making decisions during a pandemic.

One evening, I asked what she thought about traveling to visit our aging parents for the holidays. The kids, cats, and Leroy were super loud. I had to wrap my hands around my mouth to make a megaphone to ask, “Do you think we can travel safely with Moni and Nico?” The noise kept going. Amanda replied, but I could not hear. I read her lips. They screamed, “What?” I tried again without success. We went back and forth for a while. Finally, determined to be heard, I shouted, “Monico! Will a road trip be safe? For Monico!” She heard. We smiled. I am no enthusiast of celebrity portmanteaus like “Bennifer” or “Brangelina.” Monico, however, was adorable. The name-blend stuck with us. Sadly, we did not travel home for the 2020 holidays. Consequently, perhaps, by December, the first draft of the “Monico Culture and the Bayesian Archaeologist” story was born.

Read Beyond Chronology, Using Bayesian Inference to Evaluate Hypotheses in Archaeology by Erik R. Otárola-Castillo, Melissa G. Torquato, Jesse Wolfhagen, Matthew E. Hill Jr. and Caitlin E. Buck – out now in Advances in Archaeological Practice.