Reading Group, Week 18: Fun with Bayesian modeling!

This week we dared to venture into the world of Bayesian statistics. Luckily, we had the marvelous Dr. Julie Hoggarth as our guide. See below for summaries of the articles and the questions that directed our 2.5-hour discussion.

Summaries


Hamilton, W. Derek, and Anthony M. Krus. (2018) The myths and realities of Bayesian chronological modeling revealed.” American Antiquity 83.2: 187-203.
Hamilton and Krus review the history of using Bayesian chronological modeling within archaeology, offering several myths and misconceptions about the method based on their experience with colleagues. They show that there has been a boom in the use of Bayesian modeling over the past 5 years in particular, particularly applied within British archaeology as well as American archaeology. They list the following misconceptions: 1. Bayesian statistics are not scientifically objective; 2. Old radiocarbon measurements with large errors should be ignored; 3. Stratigraphic relationships between samples are needed to make a Bayesian chronological model; 4. The dates for diagnostic artifacts or time ranges should be included in models as constraints; 5. Agreement indices are useful tools for determining which models are probable; 6. Bayesian modeling is not necessary if you have an accepted site/regional chronology. Throughout their discussion of the general practice of Bayesian modeling, the authors ask chronological questions based on when activities began, ended, and the length of time the activity took place. These are all feasible questions when working in Bayesian models, given that prior information are used to model dates. The authors take the readers through the whole process from selecting samples to setting up models.


Hoggarth, Julie A., Brendan J. Culleton, Jaime J. Awe, Christophe Helmke, Sydney Lonaker, J. Britt Davis, and Douglas J. Kennett. (Accepted) Buliding High-Precision AMS 14C Bayesian Models for the Formation of Peri-Abandonment Deposits at Baking Pot, Belize. Accepted in Radiocarbon.
Hoggarth et al. present a case study on the timing of the depositional processes of peri-abandonment deposits at Baking Pot, Belize, to assess the timing for the end of political activity at the site during the Late to Terminal Classic period. Multiple hypotheses have been presented to explain these deposits, which often feature large amounts of broken pottery, along with faunal remains, figurines, and in some cases musical instruments, in corners of plazas and courtyards in sites across the Maya lowlands. These have been interpreted as rapid events, such as warfare, with the assumption that the deposits were created in a single short-lived event (day or two) in which the entire deposit was formed (e.g., the palace was sacked and the material in it were deposited in these features). Other interpretations stress more protracted processes for the formation of deposits, such as the ritual termination of ceremonial spaces or pilgrimage by post-abandonment populations. To test these ideas, the authors dated faunal remains from distinct layers of 3 deposits, using hieroglyphic texts with calendar dates as priors to constrain dates when available. They used their stratigraphic positions to place the dates into the Bayesian model, using three models to assess rapid, medium, and protracted depositional processes. The results show low statistical agreement for rapid and medium models, with very high agreement with protracted processes, and show that for Baking Pot at least, these processes included at least 3 depositional events spanning around 150 years in total.

Questions:

  1. Do we agree with Hamilton and Krus’ list of misconceptions of Bayesian modeling? Are there any points here that you think might still be problematic, particularly within their application in Maya archaeology?
  2. Given the expansion of Bayesian chronological modeling within British and North American archaeology,why don’t we see more use of these methods in the Maya area? Is this a remnant of how Maya archaeologists are trained, are large-scale dating projects too expensive, or is it not that necessary given that Maya ceramic sequences are tied to the Gregorian calendar by association with Long Count dates on monuments (or a combination of these factors)?
  3. Do we all agree that ceramic types that have been well-dated for one site/region date to the same time when they are found at other sites? Using our example of Belize Red from the last meeting, does the Belize Valley ceramic sequence nail down the the timing of Belize Red in southern Belize (or another region)?
  4. In my [Julie’s] article on Baking Pot, we are able to use Long Count and Calendar Round dates on ceramics in the deposits as a terminus post quem, to constrain the ‘time after which’ we know the deposit could have formed. Is this an under-explored area for chronology building in the Maya region or are these types of artifacts so rare that this type of method will not be likely to catch on much in Maya archaeology?
  5. Inomata and colleagues have had quite a bit of push-back from regional specialists on their Bayesian chronological revision for Kaminaljuyu and other sites. What are the main issues with applying these methods when one is not a specialist working in that region? Should archaeologists stick to those sites where they conduct excavation or can specialists working in other areas lend information or perspectives that might otherwise be missed?
  6. What do you feel would be the most important information that you’d like to learn from these types of studies and how they can be applied to the Maya area? Do you think that those studies that have been attemped (e.g. Inomata et al.) have been successful?

SCRAP Reading Group Week 17: Markets & Distributional Approach

This week we had our first meet-up of the new year for the SCRAP Reading Group. A special thank you to Dr. Bernadette Cap who joined us to discuss a series of articles on economies, marketplaces, and the distributional approach in Maya studies. Summaries and discussion questions are below.

Summaries
Eppich, Keith (2020). Commerce, Redistribution, Autarky, and Barter: The Multitiered Urban Economy of El Perú-Waká, Guatemala. In The Real Business of Ancient Maya Economies: From Farmers’ Fields to Rulers’ Realms, edited by Marilyn A. Masson, David A. Freidel, and Arthur A. Demarest, pp. 149-171. University of Florida Press, Tallahassee.

Eppich uses the concept of the ceramic microtradition (Deal 1998) and defines it as “the unique stylistic attributes belonging to specific pottery workshops and, in some cases, individual potters” (153). He applies the Distributional Approach to ceramic types and concludes that market exchange existed at El Perú-Waká because all households, regardless of rank, had Tinaja Rojo, Infierno Negro, Maquina Café. The distribution of polychromes supports a redistributive economy in the Late Classic (they occur at all households but in much higher frequencies in elite residences) and through commerce in the Terminal Classic.

Cap, Bernadette (2020). The Difference a Marketplace Makes: A View of Maya Market Exchange from the Late Classic Buenavista del Cayo Marketplace. In The Real Business of Ancient Maya Economies: From Farmers’ Fields to Rulers’ Realms, edited by Marilyn A. Masson, David A. Freidel, and Arthur A. Demarest, pp. 387-402. University of Florida Press, Tallahassee.
Cap provides empirical evidence for the presence of a marketplace at Buena Vista del Cayo in the Belize River Valley. She includes a list of marketplace activities (exchange of goods, craft production, storage, food preparation, maintenance, administration) and the archaeological expectations for each so that researchers can identify markets at other sites. Cap concludes that limestone bifaces, obsidian blades, organics, and possibly ceramics were exchanged at the Buena Vista market.

Discussion Questions

Applying the Distributional Approach in the Maya Region
Hirth (2009: 459) specifically selected non-local pottery to evaluate market exchange at Xochicalco because (1) “their foreign origin meant that all of the variation in domestic assemblages would be a function of the distribution system through which they moved” and (2) their relative scarcity and high transportation costs made them prestige goods that could have been moved outside of market exchange.

  1. If the conditions of the Distributional Approach are not met in the study (i.e. at least identifying local vs. non-local pottery), should we be applying it? What does it tell us?
  2. Local goods can certainly be exchanged via market exchange. Does this mean that a Distributional Approach, without knowledge of provenance, suggests the presence of localized market exchange?”
  3. Deal (1998) discusses microtraditions as a combination of technological, formal, and stylistic attributes. Eppich does not include technological attributes which are arguably the most useful for determining where/from whom a potter learned to produce pottery. Are ceramic types the same as microtraditions? Is this a case of type-variety being over extended?
  4. Can this extend back in time? If all Preclassic households have red slipped pottery does that mean there was market exchange?

Scale of Market Exchange”
Bernadette’s work has demonstrated the presence of markets at Buena Vista in the Belize Valley. What are the next steps for archaeologists in regions were markets have been identified?

  1. Identify markets at other sites using Cap’s criteria and document variation?
  2. Attempt to understand the scale of market exchange? I (and Sunahara 2003) think there was regional market exchange for pottery in the Late Classic in the Belize Valley.
  3. Should we be thinking regionally in places like the Belize Valley where people surely interacted regularly across the region? It seems to me there have been enough projects (artifact collections) to achieve this.

Some Alabama specific Data/Questions

Surface collection (house mounds) data:

• 39.2 % non-local pottery (southern Belize, northern Belize, Belize Valley, Maya Mountains, unknown limestone bearing regions)

• 27.5 % local to Alabama

• 33.3% mix of local and non-local (mostly areas associated with the Maya Mountains)

  1. Our compositional analysis indicates the pottery is coming from all over the place. Does that mean that Alabama had access to, or hosted, a large market with goods from all over?
  2. Is there another explanation? Perhaps variability is related to easy access to the coast? Location in a frontier zone? Some combination of markets, maritime trade, and frontier zone location?
  3. Where should we look for comparative data to understand the consumption patterns at Alabama? Is the Alabama data anomalous? Or is there just a lack of provenance/production studies?”

Ancient Maya ‘Grafitti’

Here’s a nice little write-up about ancient Maya ‘grafitti’ by archaeologist Rosamund Fitzmaurice: https://mexicolore.co.uk/maya/home/maya-graffiti

Examples from just south-west of Alabama–at the site of Lagarto in the Stann Creek District–can be found on the FAMSI website in a report (and associated Mexicon Vol. XXI 1999 article) by SCRAP friend Phil Wanyerka (http://www.famsi.org/reports/00077/wanyerka_full.pdf).

Examples of patolli boards can also be found in Elizabeth Graham’s volume “The Highlands of the Lowlands” about the archaeology of the Stann Creek District–the image below is of those found at the Kendal site.

Pottery Type #4: Maya Mopan

There are two more ceramic types left to introduce before we submit a manuscript on our newly established typology (using the names that you voted for) for peer review. The Maya Mopan type is very distinctive in the Alabama ceramic assemblage. The pottery is composed almost completely of rounded quartz sand and the color of the vessels ranges from white to tan to pink. We have only recovered a few rim sherds, and these indicate that the vessels had a fairly standardized rim diameter and were likely squat bowls and/or jars. The composition is consistent with the white soil horizon that you can see when you are driving down the Southern Highway in the Stann Creek District. We are not sure who produced this pottery because the raw materials for its production can be found across a large area so it could have been produced by people living in multiple locations in East Central Belize.

Week 16 SCRAP Reading Group: Tamales!

On Friday, the SCRAP reading group hosted a holiday cooking party online—tamales! Thanks to Claudia Alarcón and Harri Kettunen for joining us to talk about pre-Columbian food! A summary of our reading and discussion questions can be found below (provided by Shawn).

Alarcón Cacheux, Claudia and Verónica A. Vázquez López (2012) Part I: An Introduction to Mesoamerican Pre-Hispanic Cuisine. In Spice it up! An introduction to Pre-Hispanic Mexican Cooking, pp. 3-24. Workshop handbook prepared for the 17th European Maya Conference, Dec. 9-15, 2012, Helsinki.

This handbook was written in support of a 3-day (?) workshop on the history, archaeology, epigraphy, and iconography of food traditions in Pre-Hispanic Mexico for the 2012 European Maya Conference in Helsinki. Both Meaghan and Shawn had the good fortune to participate in this workshop, along with another several years later. Both were organized and led by Claudia and Verónica and their names are still whispered in hushed tones (or loudly proclaimed depending on the beverage involved) when the inevitable topic of food in Mesoamerica comes up. They have been generous enough to provide us with the full handbook for your reading pleasure, and the section on tamales (Part II) is a must. So thank you to both of them. As for Part I, the specific reading at hand, after introducing the general topic of food and outlining the sources available for its study, Claudia and Verónica break down the utensils, ingredients, preparations, and contexts thought to characterize Pre-Hispanic cuisine in Mexico and the archaeological, iconographic, and epigraphic information of these same. Of course, the original workshops paired reading, lecture, and discussion, with cooking, a model we have sought to replicate to a limited extent with this week’s reading group. Check out the recipes in Part III of the workbook.

Discussion Questions:
We’re guessing that much of our conversation will develop organically as we labour away in the kitchen, but just so that there is some structure (if needed)…

1. Maize, beans, squash and salt. We generally take it for granted that these were the staples of ancient Mayas diets. We expect that maize, beans, and squash were grown, regardless of variations in climate, environment, or soil. Further, it seems clear that, whether locally produced or acquired through well established trade networks, all communities needed salt to meet their dietary requirements and preserve perishable foodstuffs. But what of regional variability? What of the accoutrements? To what extent might we expect food traditions to vary by availability, preservation, or preference?

2. To what degree are the culinary preferences of the core expanded to the periphery? Or the present to the past? To what degree have you been able to shed light on the cuisine of your sites/regions? What challenges have you faced? What solutions have you come up with?

3. A non-archaeology topic: Food is a universal. The preparation and consumption of food punctuates our daily lives. Share some food memories. Go on! Everybody likes talking about food.

Week 15 SCRAP Reading Group: Analogy in Archaeology

This was our 15th meet-up of the Virtual SCRAP Reading Group–we’ve been meeting every two weeks since the spring (plus a couple breaks here and there). This week, our topic of discussion was on comparative approaches and analogical reasoning in archaeology. Our special guest was Dr. Rachel Horowitz. The short readings were chosen by Shawn, and below you will find his summary and discussion questions.

Horowitz, Rachel A. (2020) Between Rocks and the Maya: The Necessity of Comparative Approaches with Respect to Lithics, Methodologies, and Theoretical Frameworks. The SAA Archaeological Record, 20 (1): 18-21.

AND


Lamoureux-St-Hilaire, Maxime (2020) Comparative Approaches and Analogical Reasoning for Mayanists: Where to Go? The SAA Archaeological Record, 20 (1): 8-13.

Summary.
Both articles are derived from a special section of the Archaeological Record, in turn derived from a SAA Forum organized by Maxime Lamoureux-St-Hilaire. The two articles chosen work in complementarity, with Max’s article serving as a summary and framework for both the forum
and the section and Rachel Horowitz’s article as the case study—in this case, concerning lithic production and similarities/differences between sedentary societies and mobile foragers—and a common point of reference upon which we might build our conversation. Both, focus on the concept and use of analogy and cross-cultural comparison in archaeological analysis and interpretation.

Questions for Consideration, as per Max’s guidelines (p.9):

  1. How might we identify relevant context-specific case studies for use in cross-cultural comparison? What contexts matter most? Technology? Economy? Ideology? Language? Socio-political structure? To what extent can we profitably extend analogies based on one point of comparison to others? Are we more likely to forward interpretations that defy testing?
  2. What constitutes “appropriate space” in publications or presentations for defining the “loaded terms” we use? Is it sufficient to simply align one’s work with established bodies of literature, or should our works be essentially self-contained? What is the role/responsibility of the audience?
  3. Comparison isn’t just about noting the similarities, but the differences. Does this change with scope (i.e. micro-scalar vs. macro-scalar)? How have you explicitly or implicitly referenced similarity or differences in your use of analogy?
  4. Archaeology has always been a team sport. In what ways do you engage specialists in other fields or realms of archaeological knowledge in your work. What has this brought to the table (i.e. let’s raise a glass and take a moment to sing the praises of our colleagues)?
  5. What is the audience’s role with respect to our choice of comparative case studies?

Pottery Type #3: Hell Camp Brown

We are back to presenting our newly named pottery types (our project ceramicist is from the US and things went off the rails a bit around the election)!

The Hell Camp Brown type is not well represented in the ceramic assemblage at Alabama, but it is very distinct. The acidic soils have taken a toll prompting us to refer to this type as “Having a Bad Time Brown” in our initial classifications but it would have had smoothed surfaces that were likely slipped a red color in antiquity. The pottery was made using grog (crushed up pieces of pottery) and limestone temper which has only been documented (to date) in the Late to Terminal Classic Period in northern Belize. Interestingly, the grog temper in Hell Camp Brown most closely resembles pottery produced in the Belize Valley. We are not really sure where this pottery was made but (1) it was made in a way that has only been documented in northern Belize, (2) using grog temper that resembles ceramic vessels produced in the Belize Valley, and (3) has only been identified at Alabama in the Stann Creek District. Let us know your thoughts! It suggests to us that people were moving around and sharing information about pottery production much more than we previously realized.

Week 14 SCRAP Reading Group: Trivia Night!

This week, we took a break from reading and discussing and enjoyed a fun trivia night. In addition to categories on the 80s and Disney Princesses, we had two rounds that focused on Belizean trivia. See below for the questions. Answers are at the very bottom. Enjoy!

Trivia Rounds

ANSWERS

Week 13 SCRAP Reading Group: Digital Archaeology

Eleven participants; four countries; two hours. Once again, a great conversation about an important topic. Thanks so much to Heather McKillop for providing our readings, summary, and discussion questions (see below).

Wakefield, C. (2020) Digital Public Archaeology at Must Farm: A Critical Assessment of Social Media Use for Archaeological Engagement. Internet Archaeology 55. https://doi.org/10.11141/ia.55.9
https://intarch.ac.uk/journal/issue55/9/full-text.html

Wakefield discusses and evaluates the use of social media, in particular Facebook, in communicating field excavation information to the public during the Must Farm project in England, with well-preserved wooden posts and objects. Regular postings were critical to maintaining the digital audience, as well as postings by the same person who also excavated. Lack of funding for digital media after the excavations was an issue.

Khunti, Roshni (2018) The Problem with Printing Palmyra: Exploring the Ethics of Using 3D Printing Technology to Reconstruct Heritage. SDH, 2, 1, 1-12. DOI: 10.14434/sdh.v2i1.24590
The arch from a temple at Palmyra, which was destroyed in the war, was 3D printed at full-size from scans and exhibited in public in the USA and England. Khunti notes that the arch was out of context so poorly understood. He criticizes the project for failing to discuss the loss of human life and the destruction of cultural resources.

Mendoza, H. R. (2015) Museums and First Nations Explore 3D Printing as Mechanism for Artifact Repatriation. https://3dprint.com/104091/first-nations-repatriation/
In this web article, Mendoza discusses how the Smithsonian was able to provide 3D printed replicas of headdresses to the Tlingit who had lost many in fires. When used in ceremonies, the replicas became the masks according to the Tlingit. They later acquired 3D printers and make their own replicas.

Cook, Katherine, and Geneveive Hill (2019) Digital Heritage as Collaborative Process: Fostering Partnerships, Engagement and Inclusivity in Museums. SDH, 3, 1, 83-99. DOI: 10.14434/sdh.v3i1.25297
Cook and Hill describe and evaluate a project in which university students worked with museum collections and staff as well as descendant communities to create digital exhibits.The idea of “co-creating” exhibits with the public, descendants, and museum staff is fundamental in the projects. Problems include shortness of time, other commitments of museum staff, lack of institutional support by universities, and large time investment by faculty.

Discussion questions:
(1) For the Must Farm project, 2 people worked ½ time excavating and the rest creating and posting digital content to Facebook and a web site. Is this a good model? Other models?
(2) Khunti points out issues of lack of context and sensitivity in exhibiting 3D replicas of Palmyra. Are there better uses of 3D printed archaeology?
(3) What are our responsibilities in accuracy in 3D printing? Can 3D printing play a more active role in heritage?
(4) Cook and Hill provide a model of “co-creation,” but note many drawbacks. Is this a useful model for archaeologists and could you do this on your project?

Week 12 SCRAP Reading Group: Soilscapes, Soil Memory, and Soil Legacies

Friday’s reading group was all about soils! Thank you to Dr. Cory Sills for providing the readings, summary, and discussion questions (see below). Twelve participants in Belize, Mexico, US, and Canada. Two hours of great discussion with a great group of people.

E. Christian Wells and Marlena Antonucci. 2018. “Reframing Heritage: Cultural Soilscapes and Soil Memory.” In Field to Palette: Dialogues on Soil and Art in the Anthropocene, eds Alexandra Toland, Jay Stratton Noller, Gerd Wessolek, 447-456. Boca Raton, FL: CRC Press.

E. Christian Wells, Karla L. Davis-Salazzar, and David D. Kuehn. 2013. “Soilscape Legacies: Historical and Emerging Consequences of Socioecological Interactions in Honduras.” In Soils, Climate, and Society: Archaeological Investigations in Ancient America, eds John D. Wingard and Sue Eileen Hayes, 21-59. Boulder, CO: University of Press Colorado.

The two articles above were chosen for this week’s meeting because I (Cory) wanted to focus the discussion around geoarchaeology including soil chemistry. I am currently analyzing the sediment chemistry from the site of Taab Nuk Na, a submerged salt work in Paynes Creek National Park, that dates to the Late Classic Period. These articles, and many others, on the topic help to situate the sediment chemistry analysis in the framework of soilscapes. Additionally, I have really enjoyed the discussions in this group about public outreach and heritage education. I wanted to further add to our discussion by assigning the “Reframing Heritage” piece. What are some of the ways that we can engage the public with science? How do we situated our research so that the findings are relevant to issues communities face today?  

The manuscript titled “Soilscape Legacies: Historical and Emerging Consequences of Socioecological Interactions in Honduras” by Wells, Davis-Salazzar, and Kuehn reports the results of various soil analysis techniques to evaluate the extent of soil erosion as well as providing evidence of environmental degradation in the Palmarejo region of Honduras. The authors use a combination of geoarchaeology, pedological analysis, and archaeology to evaluate the areas soilscape. Soilscape is defined as soils that are altered directly by humans. Specific techniques including geomorphology (changing landforms over time), stratigraphy profiles, soil analysis including pH, loss-on-ignition (measures the % of organics in a sample), and extractable phosphates (% of Carbonate and amounts in mg/kg of Phosphate, Potassium, Nitrogen, and Phosphorus). Their interpretation of the results indicates that stable landforms in the area are the alluvial fans which would be most likely for settlement while terraces (less stable) would likely be cultivated. The soil analysis showed a decrease in nutrient capacity that corresponds to an increase in population suggesting greater cultivation of the soils during the 10th century.

In the manuscript “Reframing Heritage” an environmental anthropologist (Wells) teams up with an art historian and community coordinator (Antonucci) to examine the importance of soils in the heritage and transformation of brownfields in Philadelphia, Pennsylvania. Brownfields are blighted areas of a community that have been contaminated by chemicals from dilapidated buildings and/or industry. Future farmers, a contemporary-arts collective, created a Soil Kitchen where locals could bring the soil from their yard to be tested for contamination. In exchange they received a bowl of soup in a reimagined spaced that analyzed the soils on site.

Discussion Questions:

  1. How is the environment linked to social processes and behaviors? What are some examples?
  2. What meaning and memory do soils have in the Maya area? For our own projects?
  3. What are the long-term consequences of humans’ interactions with soilscapes? What Wells et al. refers to as legacy.
  4. How does social value play a role in the preservation of commodities and resources?
  5. How have Western scientific ideas/analyses hampered the understanding of anthrosols of past societies?
  6. What role can archaeology play in discussions of climate change and current environmental resource management?
  7. What techniques can archaeologists develop to aid in public understanding about scientific results and discoveries?