Survey Archaeology, Pottery, and the Chronotype System

Over the last three months there has been some discussion of the chronotype system of sampling and identifying pottery in the context of regional intensive survey projects.  The most recent critiques have appeared in D. Frankel, Review of B. Knapp and M. Given, Sydney Cyprus Survey Project. AJA 112 (2008), 182-183 and Y. A. Lolos, B. Gourley and D. R. Stewart, “The Sikyon Survey Project: A Blueprint for Urban Survey?” JMA 20 (2007), 271 (for more on this article and this exciting project see their spectacular Sikyon Survey Project web site and my less spectacular previous post).

Tim Gregory developed the chronotype system for the Sydney Cyprus Survey Project and it has subsequently been employed by Australian Paliochora-Kythera Survey Project, the Eastern Korinthia Archaeological Survey, the Troodos Archaeological and Environmental Survey Project, and my own Pyla-Koutsopetria Archaeological Project on Cyprus.  In very basic terms, the chronotype system involves both a sampling strategy and a somewhat nested terminology for artifact types designed to facilitate the reading and analysis of survey pottery.  The sampling strategy (as alluded to in the film short from Emerging Cypriot released yesterday) involves collecting every unique artifact type from a survey unit to ensure that one of each kind of artifact in the unit is represented in the collected assemblage.  It was a response to an older generation of survey projects that tended to collect only “diagnostic artifacts” which often meant rims, handles, bases, and feature sherds.  By collecting one of every type of artifact present in the unit, the chronotype system shifted the responsibility for determining whether an artifact was diagnostic from the fieldwalker (who in traditional surveys would have to decide whether a sherd was likely to be significant for establishing the chronology or function of the site) to the ceramicist who would study an assemblage that reflected the material present.  All the fieldwalker needed to do was to determine whether a sherd was similar or different from the ones he or she had already collected.

The nested terminology for artifact types involved the ceramicist assigning to each sherd a standardized chronotype which was a combination of date range (e.g. “Late Roman”, “Early Bronze Age”, or “Ancient”), fabric type (e.g. “medium coarse”, “fine ware”, “cooking ware” et c.) and description (e.g. “combed”, “black glazed”, “drip painted”).  Standardizing the way in which artifacts were described facilitated the quantitative and qualitative analysis of the survey pottery which demands that artifact types be normalized consistently across the data set.  It also provided a fairly well-developed set of artifact identifiers that could be (and was) exported to other survey projects. 

Frankel expressed concern that the chronotype system, by eschewing “conventional pottery terminology” would make inter-site and inter-project comparability more difficult.  This is certainly a concern. Inter-site comparability (e.g. Side-by-Side) is of increasing significance as more and more of the Mediterranean world is covered by intensive survey and, perhaps more importantly, as survey relies upon excavated contexts for establishing the chronology of surface pottery.  That being said, I am not as convinced that “conventional pottery terminology” is so stable that introducing a new set of standardized terminology designed for the vagaries of survey pottery will have any inherent incompatibility with more traditional nomenclature.  For the periods where my research focuses (which are generally historical), there is sufficient diversity in the conventional terminology to require some translation between projects(consider, for example, the typologies for Late Roman amphora).  As survey and excavation data sets make the slow migration to accessible digital archives which will allow for more direct comparison between projects, there will certainly be a need to create concordances of ceramic terminology that take into account not only the variety of terms employed to describe particular sherds, but also changes in identification of certain types of pottery.  Frankel has identified an area that will require the attention of archaeologists in the very near future. 

Lolos et al. critiqued the sampling strategy employed by the chronotype system.  They questioned whether a fieldwalker could consistently determine whether a sherd was “different” and therefore worthy of collection.   They also wondered if by collecting each unique sherd we would lose the ability to talk about relative frequency of particular artifact types within a unit .  Their critiques are, indeed, valid, and we have worked to address them in several recent publications (Caraher et al. “Siteless survey and intensive data collection in an artifact-rich environment: case studies from the eastern Corinthia, Greece. JMA 19 (2006),  7-43; T. Tartaron et al. “The Eastern Corinthia archaeological survey: integrated methods for a dynamic landscape,” Hesperia 75 (2006), 453-523; Caraher et al. “Pyla-Koutsopetria Archaeological Project: Second Report 2005-2006″ RDAC 2007, in press; D. Pettegrew “The Busy Countryside of Late Roman Corinth:Interpreting Ceramic Data Produced by Regional Archaeological Surveys,” Hesperia 76 (2007), 743–784; R. S. Moore, “A Decade Later: The Chronotype System Revisited,” in Archaeology and History in Medieval and Post-Medieval Greece: Studies on Method and Meaning in Honor of Timothy E. Gregory. W. Caraher, R. S. Moore, L. J. Hall, eds. Forthcoming.)  The two salient points here are as follows:

1) We regularly tell fieldwalkers “when in doubt regarding whether a sherd is unique, collect it.”  Some recent studies (see Moore (Forthcoming) and Caraher et al 2006) have suggested that fieldwalkers tend, if anything, to over collect; that is to say err on the side of caution and collect too many examples of even relatively undiagnostic sherd.  While this cannot anticipate whether the walkers have overlooked certain types of artifacts completely (i.e. artifacts that are so indistinguishable from other sherds that they are disregarded consistently as duplicates), it suggest that they did not.  In any case, the chronotype sampling method should ensure a more robust sample of the variety of material present on the surface than techniques which involve only collecting highly visible “diagnostic” (e.g. rims, handles, feature sherds, et c.) artifacts. 

2) The chronotype sampling strategy will not create assemblages that are as robust as so-called “total collection” strategies which involve the collection of all the material from a unit or a walker’s swath.  We conducted experiments in 2005 and 2006 and determined that, indeed, total collection from a 5% sample of the unit would produce an assemblage that would allow discussions of proportional representation within the unit.  This being said, it is not clear exactly what the significance of the varying proportions present in a surface assemblage means.  The formation processes that create the surface assemblage are incredibly complex and varied across periods; thus, for example, it is diffic
ult to understand what a proportionately greater quantity of, say, Classical period artifacts in a unit means.  Does it mean more Classical activity in a particular spot?  More intensive use of that spot?  More people? Or does it suggest that the Classical period material was particularly susceptible to certain site formation processes.  From my perspective we need to understand the processes that lead to the creation of the surface assemblage much better than we do today to find any significance in the proportion of pottery represented in a unit.  Of course, gross differences — like the incredible, overwhelming presence of Late Roman material at Pyla-Koutsopetria — will come out in the chronotype system as in almost all cases the more pottery there is from a particular period the more diversity there is present in the assemblage.  Thus, the chronotype system, which excels in documenting diversity, will produce a use and valid indicator of particularly prevalent periods.

The point of this post is not to attack Frankel and Lolos et al. — far from it, in fact! –  but to expand the dialogue into the blogosphere and, perhaps more importantly, shed some light on an exciting (and surprisingly robust!) little debate in the world of Mediterranean survey archaeology. 

Byzantine Pottery from Sagalassos

I was pretty surprise to see an article entitled “Middle-Late Byzantine Pottery from Sagalassos: Typo-Chronology and Sociocultural Interpretation” in the very recent Hesperia (A.K. Vionis, J. Poblome, B. De Cupere, M. Waelkens, Hesperia 79 (2010), 423-464).  It’s not so much that the subject matter is late, but that the site of Sagalassos is a Belgian project in Turkey rather than an American project in Greece.  As some of my more observant friends pointed out, Hesperia has published the results of project from Albania, so maybe this should not have caught be so off guard.  But it did and it indicates to me that Hesperia is continuing to expand its purview to include the wider world of Mediterranean archaeology. Hooray!

The article on the Middle-Late Byzantine material from Sagalassos is pretty cool as well.  The main focus of the article is on a series of 12th-13th century layers from the Alexander Hill at the site of Sagalassos.  Over three seasons of excavation, the excavators uncovered the remains of a “heavily burned” destruction layer containing the remains of a short-lived occupation containing a significant and robust quantity of 12th-13th century Byzantine pottery.  This layer appears to represent the final phase of activity on this dramatic hill overlooking the ancient site of Sagalassos.  Early occupation on the hill included a 5th-6th century basilica that was almost completely removed and a later “refuge” of some description with a fortification wall and a substantial cistern.  Apparently the church was almost completely dismantled for the construction of the later refuge. The final destruction layer, which seems to represent the final layer of occupation, may represent an effort to dismantle the refuge to prevent it from being used again.

While the site history of the Alexander Hill is pretty interesting (particularly the dismantling of the church), the real meat of the article is in the analysis of the ceramic assemblage from the final layer.  While I would like to have understood the sampling method the produced the assemblage, the authors nevertheless conduct a rigorous and thorough examination of the material and take into account both “common ware” (which we would call medium coarse, coarse, and kitchen/cooking ware in chronotype terminology) and glazed table wares (fine and and semi-fine wares in our terminology).  Some of the glazed wares were repaired indicating that the objects had significant value to their owners.  The presence of repaired pots in an assemblage associated with the destruction of the site, however, suggests (to me at least) that these vessels were either discarded by the last occupants of the refuge or brought to the site by work crews commissioned to destroy or salvage the remains of the site. I wish the article had made considered more thoroughly the formation processes at play in the creation of the assemblage from the burned layer including the possible nature of activities at the final occupation phase of the site.  If these materials were left by work crews (like the material associated with the final phase of activity at Kourion), then the diet, ceramics used, and social standing of the individuals could suggest a different assemblage from that left behind by a family.

Despite the origin of the pottery in a layer associated with the site’s destruction and short term occupation, they regard the material as sufficient diverse to qualify as a use assemblage and, therefore, suitable for making larger arguments for the nature of Byzantine cooking practices, diet, and the circulation of Byzantine glazed pottery and utility ware forms.  This was all supported by residue analysis of individual vessels and the quantitative analysis of the entire assemblage.  Apparently the individuals at Sagalassos ate more beef and game than their Late Roman predecessors (who preferred lamb and goat).  Pretty neat stuff.

The article places the material from the assemblage at Sagalassos in the context of the Byzantine Eastern Mediterranean and it will be really useful as we look to document a site with a similar history at Polis in Cyprus.  The material present at Sagalassos has comparanda both on Cyprus and, unsurprisingly, at Corinth in Greece where the study of Byzantine pottery has long held pride of place.  The careful publication of an assemblage from a site like Sagalassos expands the base of evidence for the further study of Byzantine pottery.  The appearance of an article like this in Hesperia should show scholars that there are high-quality journals prepared and willing to publish similar papers.

P.S. Lest you think that I’m just a blogger, you’ll notice that David Pettegrew, Sarah James, and I also have an article in this volume: “Towers and Fortifications at Vayia in the Southeast Corinthia,” Hesperia 79 (2010), 385-415.

A Comparison Between a Survey Assemblage and an Excavation Assemblage

For the past few months, David Pettegrew and I have been “publishing” the preliminary results of some experimental analysis conducted over the past year at the Pyla-Koutsopetria Archaeological Project on Cyprus.  As part of the experimental component to our project we were interested in documenting the relationship between the surface assemblage and the assemblage of material produced by excxavation

The archaeological fieldwork conducted on the elevated height of Vigla provided us with an opportunity to compare assemblages produced by intensive pedestrian survey and the excavation of a trench in the survey area.

Longstanding critiques of survey have suggested that the relationship between the surface assemblage and the subsurface material is too problematic for survey to be a technique used to produce a comprehensive view of the landscape. While it is true that there are more variables in the formation processes that impact the creation of a surface assemblage, we should be aware of the potential for a false dichotomy. Excavated assemblages are every bit as much a product of formation processes as those on the surface and as a result, we always have to temper our interpretation of past events with the understanding of the archaeological record as the product of a whole range of physical and cultural transformations. The goal of this comparison then is not to test the surface assemblage against the subsurface material, but rather to suggest that their correspondence indicates that the area may have endured similar archaeological processes.

As with all of our experimental units, the comparison is influenced by significant differences in the spatial comparison between the two sample areas. The surface area of our trench EU 8 represented only 6 sq meters; The two survey units 500 and 500.1 combined to covere over 6000 sq m. Any comparison of area, however, is problematic; the trench had volume and the relatively two-dimensional surface of the survey area did not.

  

The excavation unit produced significantly more ceramic material. The excavation unit produced over 4000 artifacts. By comparison, we counted anywhere from 366 to close to 1000 artifacts from our survey of various areas on the top of Vigla (depending on surface conditions and the number of walkers available), and these samples allowed us to estimate an overall artifact density of between 15,000 – 11,000 artifacts per ha. These are astronomical densities by any reckoning.

While we counted every artifact visible in our 20% sample of the surface, we collected artifacts using the chronotype sampling strategy which required us only to collect each unique type of sherd from each swath.  Using this technique in two campaigns of field walking on Vigla, we collected 963 artifacts with a weight of 27.6 kg.  In contrast, we collected and analyzed every artifact from the excavation area and this resulted in over 4000 artifacts, but this assemblage weighed less than 10 kgs more (37.0 kg) than the assemblage collected from survey.

The nature of the chronotype sampling method used in the survey makes it difficult to find a metric to compare the quantity of material collected from the survey against the quantity of material collected from excavated contexts. The key point for evaluating the correspondence between the two assemblages is not necessarily the quantities of material but rather the presence or absence of material indicating particular activity, periods, or material types present in the area.

Comparing the period date between the two collection strategies reveals that the survey collection produced more chronotype period categories (16 compared to 14) and nine of the periods represented in the survey assemblage were also represented in the excavation assemblage. In general, the survey material represented a longer chronological range with material from later periods present on the surface including material from the Late Roman, Medieval-Modern, and Modern periods. The excavated area, in contrast, produced more material from narrower periods and at least one object from a period earlier than those represented in the survey, a sherd potentially dating to the Bronze Age (for more on broad and narrow periods, see here). This artifact appears to pre-date the earliest phases of architecture present in our trenches and may not represent a past activity on the site. In general, the material from both the survey and the excavation overlap, but the excavation material offered slightly more chronological resolution than the material from the survey.

The diversity of chronological periods in the survey material would appear to extend to the chronotypes represented in each unit. The excavation produced 54 chronotypes, while the survey unit produced 57. There are 30 overlapping chronotypes between the two collection methods. While the different sampling techniques make it difficult to compare the assemblages in a meaningful way, the quantity of material from each area nevertheless provides a very basic matrix for comparing the relative quantity of various types of material from each unit. The survey and excavation both produce a significant number of artifacts from the three rather general chronotypes: ‘Coarse ware, ancient historic’, ‘medium coarse ware ancient historic’, ‘kitchen ware ancient historic’.  The excavation also produced a significant proportion of material from two additional chronotype that were poorly represented in the surface assemblage: ‘animal bone’ and ‘fineware, Hellenistic-Roman, Early’ which made up 6.6% and 5.5% of the excavated material respectively, but less than 1% of the material from the survey. The absence of animal bone on the surface of the ground could be an issue with visibility (white and tan bones do not stand out as well against the buff colored soil) and certainly preservation. 

It is notably harder to compare the potential range of activities present in the area. The chronotype method of collection privileges larger, better preserved sherds (walkers will often discard small or poorly preserved sherds if they find larger examples of the same chronotype). It also tends to under represent very common chronotypes in proportion to the total assemblage. In other words, there are fewer examples of chronotypes such as “medium coarse body sherd, ancient historic” in the survey sample in part because field walkers were instructed not collect multiple examples of this very common type of artifact. In the excavation, excavators collected every example of a “medium coarse body sherd ancient-historic” causing sherds of this type to make up a larger proportion of the total assemblage.

This tendency can be seen in the relative size of artifacts collected from the survey and excavation. From the survey, the collected artifacts were much larger and this probably reflects both our field walkers’ tendency to select larger sherds more frequently than smaller sherds for collection and the difficulty seeing the smallest sherds on the ground from a standing posture. These two tendencies combined to produce an average survey artifact weight almost 30 g as compared to the average size of an excavation sherd that was under 9 g.

The fabric groups present show some significant differences in the assemblage that we can largely trace to different sampling strategies. The survey unit preserved more coarse ware
(47%) whereas the majority of material from the excavated unit was medium coarse ware. The weight of the two fabric groups as a percent of the total assemblage sheds more light on the situation. Medium Coarse wares from the excavation represented 53% by volume, but only 22% of the assemblage by weight. In fact, the average weight of a medium coarse ware sherd is less than 4 grams. In other words, many of the medium coarse fragments of pottery from the excavation are quite small, and these sherds are the most likely to be overlooked during survey. Cooking/kitchen ware, coarse ware, and amphora represented the other significant parts of the excavation assemblage. As the chart below indicates the percentage of weight is significantly different from the proportions determined by counts. In weight amphora and coarse wares combine to make up the majority of material.

The material from survey shows different proportion, but these proportions are significantly biased by our sampling technique that suppressed the collection of redundant artifacts.

Coarse ware is the most common fabric group by quantity and makes up the majority of material by weight. Amphora sherds, which tended to be handles or very large body sherds, represent a massive quantity by weight, but significantly lower percentage by quantity. The opposite is true of medium coarse ware and kitchen/cooking ware.

Similar tendencies are visible from rim-base-handle-sherd analysis (for more on R-B-H-S Analysis, see here). 

The results of this comparison suggest that for the height of Vigla the most major differences between the assemblage produced by survey and that produced by excavation are tied to the different sampling strategies used in these different contexts. At the same time, the basic patterns present in the survey assemblage were also present in the assemblage from the excavation.  The presence of material from the Classical and Hellenistic period, the presence of fine ware, kitchen/cooking ware, and utility wares, and the almost complete absence of earlier material allows us to argue that the site was first occupied in the Archaic to Classical period, saw domestic activities, and then was used less intensively in later periods.  This close correlation of survey and excavation assemblages reflects, in part, the stability of the soils on Vigla and the relative lack of erosion, on the one hand, and the lack of intensive activity during later periods, on the other.  In other words, the surface assemblage and excavation assemblage enjoyed similar sets of formation processes which produced similar assemblages. 

Broad Period Artifacts and Survey Analysis: Quantifying what you don’t know

By far the most vexing issues facing most survey projects is the analysis of artifacts datable only to very broad periods of time (a point I brought up in my blog post from last week).  In the work of the Pyla-Koustopetria Archaeological Project, these artifacts are the equivalent to objects of “unknown date” from other survey projects.  The chronotype identification system required our ceramicist to date each artifact even if these dates are exceedingly broad.  As a result, we have significant quantities of artifacts dated to periods that exceed 1000 years in length. These broad periods tend to represent two types of artifacts. 

1. Artifacts that do not fit into any known typology such as body sherds without particularly characteristic marks, fabrics, or shapes.
2. Artifact types that remained in use for long periods of time.  This is most often the case with various kinds of coarse and medium coarse utilities wares probably produced from local fabrics.

In some cases, the fabrics or shapes can tell use enough to allow us to group the artifact into a relatively well-defined, yet still exceedingly broad, date range.  For example, the most common period for an artifact dated to a broad period is “Ancient Historic”.  This is a date range that extends across the entire period of historical antiquity on the island of Cyprus: 750 BC – AD 750.  Almost all of these sherds (89%) are body sherds. The artifacts datable to this period appear over 77% of the total area of our survey and in 84% of the units where artifacts occur.  Statistically, the distribution of “Ancient Historic” artifacts correlates more closely to the overall artifact densities across the entire study area than any other period, broad or narrow (the correlation is .674).  This is particularly significant because artifact counts and the number of artifacts assigned to a particular period are independent variables: our artifact counts are based on the total number of artifacts visible on the ground according to clicker counts and the number artifacts dated to a particular period is a subset of the number of artifacts sampled from the units.  Finally, the fabric types present in Ancient-Historic period more or less parallel the fabric groups present in narrower, better-known, or at least more clearly defined periods (e.g. Classical or Classical-Hellenistic). For the Koutsopetria plain, for example, “Ancient Historic” material appears as coarse ware, medium coarse ware, and kitchen/cooking ware which finds rough parallels with the groups of material present from other periods and the general functional character of the area (for those of you keeping track at home, we call the Koutsopetria plain Zone 1)

Other broad periods from our site represent small quantities of obscure material that stands outside traditional typologies.  For example, there are only two sherds assigned to two chronotypes dated to the Ceramic Age (a Red Micaceous Pithos and coarse ware). Only four sherds assigned to four chronotypes received the generic Ancient date (Ancient Lekane, fineware, kitchen ware, medium coarse ware). Only one chronotype, amphoras, receive the designation Post-Prehistoric.

In old days of survey, sherds dated to broad periods tended to be neglected either at the analysis phase, or more commonly at the sampling and collection phase.  The vast majority of broad period sherds are body sherds (85%) and most of these would not appear to be diagnostic. As a result many traditional collection strategies that privileged diagnostic sherds (feature sherds with distinct marks, rims, handles, bases) would have overlooked broad period material. More recent work has at least assigned the designation of “unknown date” to these broad period artifacts, but rarely do they appear documented in the survey publication.

This material is difficult to correlate with past human activities. At best, it reinforces the notion that certain types of productive practices may have endured for long periods of time without much in the way of visible changing.  It suggests that certain vessel shapes, fabrics, and pottery categories may have continued to serve basic functions within the community, the household, and the economy for long periods of time as well. In Braudelian terms, the apparently long, slow, and relatively unchanging character of such a large part of our ceramic assemblage represents the slow swells of the sea.  The more closely dated and rapidly changing character of fine wares or even the more diagnostic parts of the vessel , for example, which tend to allow us to produce our narrow period assemblages, show the more fickle and rapidly changing nature of ancient ceramic habits.

The value then of our effort to understand the distribution and character of artifacts datable to broad periods from PKAP is that they give us a real measure of how much we do not know about material from our survey area.  And at the same time, reveal that much of the most basic practices typical of the ancient world likewise continues to elude our grasp.

Some Notes on RBHS Analysis of the Pyla-Koutsopetria Survey Data

No RBHS is not a local high-school to whom I’ve outsourced PKAP data analysis, nor is it a new type of digital hi-def television.  Those letters stand for Rim, base, handle, sherd and represent the basic parts of a ceramic vessel.  Since most of the vessels one finds in survey and even excavation are not whole or are broken and mangled, documenting the rim, base, handle, and sherds from each vessel is an important way to understand how we as archaeologists are able to identify an particular object and assign it to a date, function, and even, sometimes, place of manufacture. It is also helpful in secure, stratigraphic contexts (that not in an unstratified survey context) for identifying the minimum number of possible vessels of a particular type because we know that some kinds of vessels on have, say, one-handle, then a four handles would represent at least four vessels of this type.

David Pettegrew’s research has really set the stage for applying this kind of analysis to the PKAP survey data. He has argued that certainly highly diagnostic artifact types (for example Late Roman 1 amphora handles or Late Roman “combed ware” body sherds) can distort the chronological distribution of material at a site.  Periods characterized by less diagnostic artifact types tend to be less easily associated with a narrow chronology or function and under represented in relation to period defined by more easily identified vessels types.  So isolating the way in which particular periods become visible using our Rim/Base/Handle/Sherd analysis becomes an important to critique our survey data.

Fortunately, the basic system that we use to document our ceramics, the chronotype system, took into account rbhs. The chronotype system required the ceramicist to separate and document as a group, called a batch, according the extant part of each type of vessel present . In other words, we counted in one batch all of the rims from, say, a Roman Amphora and in another batch all the handles from the same kind of amphora. This has allowed us to parse quite finely the character of our assemblages and its relationship to our ability to identify particular types of artifacts based on their individual parts.

So here are some basic observations:

• Of the 19 periods with more than 20 sherds collected using our standard survey procedure, 13 counted the majority of artifacts as body sherds. In other words, for most periods, body sherds represent both the most common and the most chronologically diagnostic type of material.
• Only for the Archaic period were the majority of artifacts identified by one part of a vessel, and these almost all came from one type of vessel, so-called Archaic basket handled storage jars.
• Of the 258 chronotype (that is discrete types of artifacts) that produced extant parts (some chronotypes, like shells or wall plaster fragments, do not produce extant parts that we can easily record), 138 of 55% of these chronotypes were identifiable based on only one extant part. 76% are recognized by only two extant parts and 90% by three. 99% by four extant parts (mainly RBHS).  In other words, most artifacts are only recognizable by one part of the vessel.
• It is interesting to note that the number of chronotypes associated with a particular period has almost no influence on the average number of extant parts by which a vessel is identified. Large number of chronotypes identifiable by a large number of extant parts (4+) come from Roman (40), Late Bronze Age-Hellenistic (18), Ancient Historic (39), Hellenistic-Early Roman (24) vessels. At the same time 4 or more extant parts also appeared for periods with fewer chronotypes, like Classical-Roman (6), Late-Cypriot II-Late Cypriot III (4), and Post-Prehistoric (4).  This means that while the majority of sherds from each period are body sherds, they nevertheless have vessels that are identifiable based on other parts of the artifact.  In other words, our ability to date artifacts to a particular period is independent from the number of vessels with identifiable extent parts. Some periods have three or four chronotypes with lots of identifiable fragments; others have 25 different chronotypes with a mix more and less easily identifiable artifact types.  There does not seem to be a pattern.
• Far more central to the number of parts of the vessel that we can identify is the kind of vessel and their function. Kitchen/Cooking ware produce the most possible extant parts (4+) followed by coarse ware and amphora chronotypes (3.8). Medium coarse ware produced 3.5, while pithos, semi-fine, and fine all produced 2.4 or fewer extant parts per chronotype. This likely has more to do with the shapes of the vessel than the size of the vessel.

This kind of analysis may seem tedious and complicated, but it is important to understand how bias in our ability to identify a particular type of artifact can influence the kinds of chronological and functional landscapes that we create from survey data.  In examining our data in this way, we can really see the point of contact between what our ceramicist does in placing artifacts in particular classes and our historical reconstructions of the landscape.  The entire world of Pyla-Koutsopetria is literally born from the data gleaned from individual artifacts.

Even More Experiments in Intensive Pedestrian Survey

Even more guest-posting brilliance from our esteemed guest blogger, David Pettegrew, the co-director the Pyla-Koutsopetria Archaeological Project and the 2010 Cyprus Research Fund speaker.  Be sure to check out his posts on Tuesday, Wednesday, Thursday, and yesterday.

Over the last few days (here and here), we have been discussing the results of an experiment we carried out 2010 in order to assess the relationship between the number of artifacts we see in pedestrian survey and the number actually on the ground.  You can read about the first two phases of these experiments here and here.

Today we consider the kinds of artifacts that we observed during total collection and the sorts of material that made up the surface matrix.  When we set up the experiment, we consciously decided not to collect artifacts via the chronotype sample as we normally do in our pedestrian resurvey.  What crueler thing could one do to the project ceramicist than overwhelm him with 1,000+ surface artifacts? (After all, the logic of sampling is to manage human resources more effectively.) Because we didn’t identify the artifacts from the total collection grid according to chronotype as we did for the survey units, we limited the kinds of comparisons we can make between the pedestrian survey sample and the total collection.

Even still, there were still some things we could do to give us a sense of the kinds of material on the ground, especially their fabric and functional attributes.  How much of the surface assemblage of a high-density unit at Koutsopetria consists of cooking ware, coarse wares, coarse wares with surface treatment like combing, and table wares (slipped or unslipped)?

To address this question in part, we sorted all pottery from each total collection unit into three basic fabric classes: semi-fine and fine ware (whether decorated or not), cooking ware, and medium-coarse and coarse wares (including amphora sherds).  The results below show the count of each of the categories in each of the total collection grid squares and give in parentheses the percentage of that fabric group in terms of the total number of potsherds in the unit.



 

Fine ware constitutes 7.6% to 15.4% of the number of potsherds in each subunit; cooking ware only 1.7% to 5.4% of the total number of potsherds; and coarse wares consistently 80.2-87.2% of the overall assemblage.  Unsurprisingly, for a predominantly Late Roman assemblage, the great majority of the sherds are coarse, a small percentage are fine, and tiny percentage are cooking.  The disparity between coarse wares, on the one hand, and fine and cooking wares on the other would have been even greater had we compared weight instead of count, since most fine and cooking ware sherds are thin-walled and small.

We also counted the “parts” of the vessel according to the standard ceramicist categories of rims, bases, handles, shoulders / necks, and body sherds.  Rims represented 2.9-7% of the total sherd count, bases less than 2.2%, handles from 2.2 to 5.3%, neck and shoulders typically less than a percent. Body sherds typically represent over 90% of the surface assemblage.

Finally, we tabulated the data in a slightly different way, breaking down the surface assemblage for each subunit by both fabric group and part.  The results shown in the table below suggest that this Late Roman assemblage includes for fine wares mainly body sherds (73.8% of fine wares) and rims (19.5%), for cooking ware mainly body sherds (84.5% of cooking wares) and handles (6.9%), and for coarse ware mainly body sherds (92.9% of coarse wares).  

Coarse ware body sherds make up 79.5% (n=1474) of the total number of sherds (n=1,854) counted for all 4 subunits.  By contrast, fine ware rims make up 2.2% of the total pottery assemblage and cooking ware rims form only .11% of the total pottery assemblage!!!  The 71 fragments of slipped and glazed fine ware (i.e., not including fine ware lacking clear glazing or slip) represent only 3.8% of the total number of potsherds counted (n=1854).  These few black glazed Classical-Hellenistic sherds and red slipped Roman-Late Roman sherds are the typical objects used to provide most of the chronological information for dating archaeological sites but they represent less than 4% of our surface assemblage of this unit at Koutsopetria.

Finally, it is worth asking what percentage of coarse body sherds have surface treatments and decorations like grooving, combing, and ridging — the kinds of surface treatments that usually lead to them being collected in most regional surveys.  To address this question, we counted the coarse sherds for two of the subunits (G1 & G15) with spiral grooving, combing, or wheel ridging.  The 66 sherds represent 12.5% of the 526 coarse body sherds from those subunits and 9.8% of 672 total sherds from those units.  These “diagnostic body sherds” then are more visible than glazed and slipped fine ware but still quite unrepresentative of the surface pottery as a whole.

I suppose our next steps with the results of these experiments are to compare them with 1) the chronotype sample from the broader survey, and 2) the data from subsurface excavated deposits.  I think the interesting results of the experiment certainly justified the time it took to totally collect the subunits and will allow us to understand how close our chronotype sample is to the population of ceramic artifacts on the ground.

Processing Pyla-Koutsopetria Pottery

Another post with help from our guest blogger and 2010 Cyprus Research Fund lecturer, David Pettegrew. Check out the first in our series of posts here.

In 2010 the Pyla-Koutsopetria Archaeological Project was above all the year of the potsherd.  Excavations generate a lot of material.  Our thirteen Excavation Units in 2008 and 2009 generated pottery at rates faster than our poor ceramicist, Scott Moore, could read and pottery began to pile up at the museum while we were finishing our work.  We promised Scott that 2010 would be different and we were fully committed to getting the material read.  In fact to our surprise, some bureaucratic snafus getting our permits to do fieldwork prevented the collection of additional materials, and allowed us to devote more time to processing the material collected in past seasons.  So rather than venturing out into the field, we spent each mornings out at the museum processing hundreds of bags of ceramic artifacts and our afternoons processing digital data from previous years.  The result of all this is that we caught up.

Now to the untrained eye, ceramic processing looks like a bunch of people doing just one or two different tasks.  If you had come to Larnaka and peeked into our work space, you might only discern a couple of obviously different activities say, washing vs. analysis.  But the team was conducting a wide range of different tasks related to the finds.  The most obvious and important preliminary activity involved washing artifacts.  There were a slew of them to wash, 147 bags to be exact, each bag containing dozens, sometimes hundreds of artifacts.  Student enthusiasm for washing artifacts declined over a period of a week and a half but that is to be expected.

Dallas Deforest photographed every catalogued artifact at a resolution high enough to be published.  In 2010, Dallas took over 1,200 digital photos of our catalogued artifacts to join the 3,100 artifacts taken in previous years.  Two of our PKAP veterans from 2009, Becky Savaria and Melissa Hogan, began the process of labeling these photos.  In late June, David spent about 10 additional hours getting all the photos in order.  Now we have an archive of 4,300 digital photos of the 700+ catalogued artifacts and uncatalogued artifacts.

Building 13 was the central hub of ceramic analysis.  Our co-director and golden child, Scott Moore, spent 3 weeks analyzing the ceramics from excavations including those occurring in the 1990s at the site of Koutsopetria and our more recent ones at Koutsopetria and Vigla.  Scott analyzed the pottery in two different ways.  First, he “scanned” less significant contexts from stratigraphically unimportant matrices like the plowzone, the kinds of contexts where reading pottery in great detail is not all that beneficial.  “Scanning” involves 1) sorting pottery into broad categories based on fabric groups (e.g., fine ware, cooking / kitchen ware, and coarse ware); 2) setting aside the most distinct and diagnostic artifacts; 3) making basic observations about the context as a whole on a scanned unit form; and 4) analyzing in greater detail the most diagnostic pottery.  Indeed, scanning is common in Mediterranean urban excavations where excavations might easily produce hundreds of thousands of artifacts (or millions).  The more important contexts Scott read more thoroughly by identifying every artifact with a specific chronotype.  A chronotype is simply a specific, limited identifier for known groups of pottery that combines date, potential functions, shape, and appearance.  The point is that Scott read (and this is an estimate) 200 contexts while in Cyprus this year.

The other activities going on in Building 13 were data management (Bill), illustration (Becky Savaria, Melissa Hogan) and artifact cataloguing.  David, Dimitri, and several students wrote more detailed catalog entries for particularly significant finds from the survey and excavation.  In 2007, we completed a formal catalogue of the most significant artifacts from our archaeological survey.  This year, we completed the catalogue of artifacts recovered in the two years of excavated soundings.  The combined total of catalogued artifacts now exceeds 700.  While it is unlikely that we’ll be able to publish a catalogue of 700 different artifacts, we plan to eventually release this complete catalog in a digital form and publish on paper a smaller number of “greatest hits”.

We recorded the following information for each artifact in our catalogue.

Artifact Number:

Dimensions:

Munsell:

Description Fabric:

Description Shape:

Description Decoration:

_______________________________

Besides this work, we did a variety of more specialized work.  Sarah Lepinski and Bill completed the documentation of the architectural and painted plaster from the excavated area at Koutsopetria producing a complete catalogue of material for publication.  Sarah’s pain-staking examination of the plaster from the excavated area has revealed not only several phases of reconstruction and redecoration that remained obscure in the stratigraphic record, but also import clues about the architecture and even construction techniques used in the building.  Nearby, several students completed a special project analyzing artifacts from the plowzone which we plan to report on later in the week.

In sum, at the end of the 2010 season, we can offer this summary of the quantity of artifacts processed by team PKAP between 2003 and 2010:

Total number of units processed (from both the survey and the excavation): 711.  Each unit represents a discrete archaeological context either in terms of stratigraphy, method, or horizontal space in the survey area.

PKAP Pottery Processing by the Numbers

Batches of artifacts processed: 12,900.  Scott divides the pottery from each unit into batches of similar types of artifacts based on the artifact’s fabric, the part of the vessel represented, and the chronotype.  Over the past 8 years Scott has processed slightly fewer 13,000 batches.

Total number of artifacts processed: 37, 141.  Each batch has an average of 2.9 artifacts.

Total weight of artifacts processed: 1,482.1 kg or 3,208.7 lbs or over 1.5 tons of pottery.

Artifact Photos Taken: 5,500

Artifacts Catalogued: 727

 

The Personal Archive

I’ll admit that I am currently obsessed with Omeka (and particularly excited about their new foray into cloud hosting).  As any reader of this blog knows, it’s a free, open-source web-publishing platform.  And I have begun to use it extensively to publish images from my archaeological work in the Mediterranean.  The software is powerful and relatively easy to use. I’ve managed to build three archives so far.  The first included the works of Ryan Stander who was the artist in residence at the Pyla-Koutsopetria Archaeological Project this past summer.  The second, which I featured in this blog yesterday, included images taken of the site of Lakka Skoutara over the course of 9 years showing archaeological formation processes playing out in the Greek countryside.  Yesterday, I uploaded a series of maps documenting the distribution of material across our study area in Cyprus.  The maps show the distribution of artifacts by chronotype across the coastal zone of Pyla Village, and these maps will be linked to places within a working draft of a chapter for the upcoming PKAP monograph on the distributional analysis of material at the site. 

Distribution of Hellenistic to Early Roman period artifacts

Distribution of Early Roman period artifacts

Eventually, a working draft of this chapter (part of which have appeared, albeit in very fragmentary forms in this blog in Thinking Out Loud One, Two, Three, Four) will appear on my Scribd page or, better still, in my Omeka archive alongside the other maps and images using their clever Google powered document viewer plug-in.

None of these applications took me more than a few hours to find my comfort zone and I can uses these applications to continue to expand the personal-professional archive that began with the blog.  Each archive is designed to accommodate different types of material, operates with slightly different principles of organization, and has a different aesthetic of display (or user-interface as the kids call it).

The scholarly process becomes more transparent and de-mystified.

Survey Archaeology Finds as Data

One the small arguments that I make in our paper on re-analyzing the survey finds from the Ohio Boeotia Project is that the changes in technology have influenced the way that data were recorded in archaeology. One thing that is particularly noticeable in the data is that little effort was made to normalize the finds data. This is not because the project was not imagining that their data could be analyzed quantitatively. In fact, the density or distributional data was collected on paper forms that were suitable for direct entry into a spreadsheet type program.

OBE Field Recording Sheet

The finds data on the other hand was collected in a way suitable for a text type catalog. Such catalogues have been a standard part of archaeological documentation for a century. They are typically include measurements for the object and then a textual description of the fabric, shape, decoration, and date of the object with some notes on comparanda. Such thorough textual descriptions of objects is useful for establishing the identity of fossil types in an excavation context. In other words, these objects serve to date stratigraphic layers in excavation and describing them accurate is important for establishing the validity of the identification of the object.

With the introduction of “New Archaeology” (or processural archaeology) in the early 1960s, there emerged a greater interest in quantification and quantitative methods for documenting past human activities. The tools to perform these kinds of quantitative analysis, however, were expensive and time consuming (often involving processing punch cards, expensive mainframe computer time, or even tedious and error prone hand calculations). The increasing availability of personal computers in the first years of the 1980s paralleled the development of important software packages for organizing data on desktop computers. IBM’s iconic DB2 came out in 1983 as represented the first SQL driven desktop database. The same year saw the introduction of a powerful new version of the longstanding statistics package SPSS (SPSS-X). Moreover, the portability of both hardware and software made it possible to enter data in the field. This undoubtedly shed light on the practice of data collection in direct contact with data entry (if not on the fly analysis). The desktop computer, SQL driven database software, and new statistics packages put complex statistically driven archaeological research in the hands of even the smallest intensive survey project.

Apple Computer Advertisement from 1985

The Ohio Boeotia Expedition worked on the cusp of these significant changes concluding in 1982. As a result, they collected quantitative data on artifact densities (which could be easily calculated by hand), but did not collect the finds data in rigorously normalized way. This is not to say that the data was not collected systematically. In fact, the systematic and robust collection of finds data has made it possible to normalize significant parts of the finds notebooks. The results can then be projected across the transects that were remapped into our GIS.

Classical Period Finds

Hellenistic Period Finds

Late Roman Period Finds

With time and creativity these data could be translated into chronotype data. The chronotype system is the systematic recording system that we used to document finds from the Eastern Korinthia Archaeological Survey and in the Pyla-Koutsopetria Archaeological Project (as well as several other significant survey projects). We are gradually translating the context pottery from the Ohio State Excavations at Isthmia into this same system. This will create a foundation for some kinds of cross project analysis. At the same time, it will not eliminate the need for careful catalogue entries. The practice of recording careful descriptions of artifacts central to chronological and functional arguments will continue to remain central to archaeological documentation. In fact, the improved ability of desktop database software and “natural language” search engines will make these descriptions increasingly susceptible to the same kind of quantitative analysis as more standardized (and in most cases abbreviated) forms of notation.

Meta-data Monday

I haven’t run a meta-data Monday for some time now in large part because my blog hasn’t hit any notable landmarks.  As a blog lives longer, those landmarks became fewer and farther between, I guess.  The reason I am posting a meta-data Monday post now, is that I have heard several times over the past weeks someone quip that no one really reads academic blogs or, more agnostically, that there is no way to know whether anyone reads academic blogs or the like.  Of course, on some level there is no way to know whether anyone reads anything, but putting aside that relatively extreme position, I thought that making a post that includes some of my blog’s data would at least put my mind to rest.

My blog has been in existence for about 2 1/2 years and over this time, I’ve had about 62,000 page views.  While this pales in comparison to high volume, professional blogs which might see page view numbers like this for a single day, these numbers nevertheless make it hard to deny that someone reads or at least looks at my blog.  The 62,000 + page views are over the blogs 549 posts (I guess I could have waited a day and posted this in celebration of my blog’s 550th post!).  Lamentably, there are only 265 comments on these 549th posts. 

Using Google Analytics, I can show that I have had visitors from 141 countries.  My blog has received the most hits from:

1. United States
2. Greece
3. U.K.
4. Canada
5. Italy
6. Australia
7. France
8. Germany
9. Cyprus
10. Turkey

I’ve had visits from every U.S. state with the most popular states being:

1. California
2. North Dakota
3. Pennsylvania
4. Minnesota
5. New York
6. Ohio
7. Illinois
8. Florida
9. Texas
10. New Jersey

Google Analytics allows us to mine all sorts of interesting data.  For example, the ever popular browser profile of my readers:

1. Firefox (45%)
2. I.E. (39.57% with 27.73% on I.E. 6.x for those of you who get upset about that kind of thing!)
3. Safari (8.13%)
4. Opera (2.93%)
5. Chrome (2.47%)
6. Camino (<1)
7. Monzilla (<1)
8. Netscape (<1)
9. Konqueror (<1)
10. NetFront (<1)

Windows users account for 80% of my traffic with Macintosh representing 18% and Linux 1%.

The top referring domains (i.e. how do folks find my site):

1. Google
2. Typepad.com
3. und.edu
4. pkap.org
5. yahoo.com
6. Kourelis.blogspot.com (Objects, Buildings, Situations)
7. archaeology.org  (the web-domain of the Archaeological Institute of America)
8. Iconoclasm.dk (Troels Myrup’s excellent blog)
9. grandforkslife.blogspot.com (the Grand Forks Guy’s local blog)
10. twitter.com (largely via my Twitter feed, which you should follow, by the way!)

To round out this list, here are the top referring blogs:

4. Thoughts from West Melrose
5. Rogue Classicism
6. Electric Archaeologist
7. Ancient World Bloggers Group
8. Historical Archaeology in the Ancient Mediterranean
9. Research News in Late Antiquity
10.  Antiquated Vagaries

The top ten posts based on page views:

1. Early Christian Architecture and Hybrid Space
2. Real Snow in Athens
3. A Walk through Byzantine Athens
4. The Byzantine and Christian Museum
5. Blogging Archaeology or the Archaeology of Blogging: Metablogging the Ancient World
6. The Early Christian Ecclesiastical Architecture of Cyprus: First Impressions
7. Punk Archaeology: Some Preliminary Thoughts
8. Suburban Archaeology A (Detroit) Jewel in the Attic
9. Survey Archaeology, Pottery, and the Chronotype System
10. Emerging Cypriot: An Archaeological Documentary

And just for fun, here’s my Wordle Cluster:

So, thanks to all my readers and referrers!