Types of Archaeological Data
Lesson Objectives: Understand sites, artifacts, sampling, and other basic concepts.
What kinds of things does archaeology study? There
are both materials, physical things such as artifacts or stains
in the ground, and data, information such as measurements,
directions, and associations. Discussion of this is very straightforward
in your book. [Passing around of various kinds of artifacts, ecofacts;
display on the screen photos of materials and sites.]
What are artifacts? Things made or modified by people, and
they are usually portable, as opposed to features, which are
stains in the ground or other non-portable things such as buildings.
I did work at a bison kill site out west where a postmold, a dark stain
in the ground left from a large decayed log post, was carved out in
a huge block and hauled to the Smithsonian for more careful study, so
portability is a relative term. Even whole ships and other constructions
can be raised or moved 
What are ecofacts? Natural items used by people
or somehow otherwise having cultural associations, such as the many
shells left in the shell middens or garbage piles of prehistoric Floridans
and other coastal peoples. What are sites? Locations of human
activity that would have left artifacts, features, and ecofacts. They
do not need to be habitation sites, but can be for special purposes
or limited activities, such as stone quarries, cemeteries, sunken ships,
or isolated temples. Often it is hard to define a site archaeologically,
if it is one artifact it may have been dropped; one piece of an artifact,
such as a sherd of pottery, is even more problematic. Similarly, site
boundaries and divisions between one site and the next in a high-use
area are difficult to establish sometimes, and usually defined operationally
for the situation at hand or defined by the official state definition.
In Florida, we can define a place where we find a handful of stone chips
or flakes of chert (the New World stone often called flint) as a site.
A single stone tool could be listed as an isolated find.
How can we categorize the processes that produce archaeological
sites? Your book defines them as the behavioral processes,
what the living people did to leave the remains of the site, and the
transformational processes, what human and natural processes
transformed the evidence after the original people were gone. Behavioral
processes listed include acquisition of the material (from that quarry
site we get the stone), manufacture (we make the stone tool by chipping
it or flintknapping), use (which puts wear and other evidence on the
stone tool), and deposition (either accidental, by losing something,
or deliberate, by throwing it away).
All of these can be included under the heading of site formational processes, with two kinds, the human and the natural. After the original people are gone later humans transform the landscape, reusing old materials, plowing them down, covering them, and so forth. Modern human action is responsible for destroying hundreds of archaeological sites per day in the U.S. and across the world, mostly because people do not realize what they are destroying or how important it is. This is why education in the stewardship of the past is so important worldwide.
Natural processes can be classed as physical
(erosion, rain, gravity), chemical (weathering, rusting), or biological
(animals burrowing, bacteria decaying), and can work at the small scale
(rotting away of a wooden artifact) or the large (rotting away of a
whole village of wooden houses). They can be subtractive, destroying
the materials, or preservative, burying the materials in river flood
sands or volcanic deposits.
The vagaries of the archaeological record severely bias our archaeological interpretations. What are the kinds of materials best preserved? Usually stone and ceramics. What is usually not preserved? Usually organic materials such as wood, animal flesh and bone. What conditions preserve organic remains best? Freezing, drying, or keeping wet all the time. The Florida climate, for example, is wonderful for organic decay because it is hot and cold, wet and dry. The soils are acidic, insuring rapid decay of organics. But in a shell midden the basic nature of the shell contributes to good preservation of animal bones, such as those passed around.
At the Windover site near Cape Canaveral, where Archaic
period Indians buried their dead in a pond, the constant wet environment
preserved wood, bone, grass matting, and even the people’s brain
matter inside their skulls. Your book pictures other preserved people
from Danish bogs, with all their clothes and even some with ropes around
the neck indicating they were killed and thrown in there. On the desert
coast of Peru, the lack of rainfall for years at a time guarantees the
preservation of skin, feathers, textiles, and other perishables. Frozen
Inca mummies have been recovered from high-altitude ceremonial sites
in the Andes, and other frozen past people have come from the Arctic
and elsewhere. There is even the frozen 5,300-year-old Italian guy from
the Alpine glacier who we will see later in the class.
Your book has a nice illustration of site formation
processes on page 62, showing the sequence of events from prehistoric
hunting camp to modern highway construction.
Besides the materials themselves, what information is recorded in archaeology? Very important is the context of provenience, or all the information on context in which something is found, including exact place in three dimensions and association with other items. Provenience might include everything from the date and name of the investigator to the level number in the excavation unit.
What is a research design? It is a plan for how the archaeological project will be conducted in order to meet its goals. One of the first tasks is to determine methods of investigation.
All archaeology is done by sampling. Why take a sample instead of digging up the whole thing? If you had a billion dollars to dig up a whole site, why should you not do it? Conservation archaeology is the view that we should NOT dig very much, that we should analyze well what has already been dug, that we should preserve sites, especially because our techniques today are probably very crude compared with what will be available in the future. In the 1930s, the Great Depression, make-work programs resulted in lots of archaeological excavation in the southeastern U.S. and elsewhere in the country. When they dug up many famous mounds and other sites, they did not save the charcoal or animal bone because it was considered junk; they just wanted the artifacts. Now we know that we could radiocarbon-date charcoal, and we could analyze the animal bone to see what people ate and what species they used.
Archaeology is the only science that destroys its subject matter during
the course of the work. A chemistry experiment can be redone many times,
for example, but once an archaeological site is dug, it is gone. So the
methods used must be as careful and complete as possible, and still you
are losing information and materials. As methods improve we see what
we did not do last time.
Meanwhile, then, we also sample because there is usually not the time and money to do more than a good sample. What is the sampling universe or data universe? It can be an entire archaeological site, a county, or other land area in which we wish to find archaeological sites. It can be a portion of a site that may answer our research questions, such as the village site next to the mound.
What are the sampling units? To get Nielsen
ratings they use television sets or households to find out what people
are watching. What do archaeologists have? We can divide the site along
grid lines into 1-meter or 10-meter squares; we can divide the county
into already existing legal sections, which are square miles; or we
can set up other sampling units that are useful and easy.
What are the types of sampling? Beyond the strategies of data acquisition described in your book, we need to describe sampling strategies. What is random? Random sampling means choosing sample units based on a strategy that allows any unit to have an equal chance of being chosen. Random is NOT throwing your trowel into the air and digging where it lands. Why not? Because you tend to throw in a particular direction. To do random sampling you can number all your units and get a sequence of random numbers from a math book table or a computer or the decimal places of the number (pi, proven to be random) and use them to pick which units to investigate. The advantage of random sampling is that you do not impose your biases upon the data. The disadvantage is that you may get clustered units.
What is systematic sampling? It calls for
the investigation of sample units according to some designated system,
such as every third unit or every 100 meters. The advantage is that
you effect good coverage of the study area; the disadvantage is that
your system may duplicate some past cultural system. Digging every 40
feet in a Neolithic village with houses spaced 40 feet apart will mean
you uncover a west wall in every unit.
What is stratified sampling? You can stratify the sampling universe, divide it into areas based on environmental, architectural, or other criteria, then sample within the individual areas. For example, a site may contain a conical mound, a pyramidal mound, a plaza, and a village area; you could section off these areas and be sure to take a sample in each. Or a tract of land could have a stream valley, a hilltop, a swamp, and a coastal zone that could each be sampled. Within the different strata you might use random, systematic, or some other sampling method. The advantage of this type is that there is no clustering, and your knowledge of the land and culture can be used to ask better questions than just what is there. This could be the disadvantage as well, since your views may reflect your own culture and not that of past peoples.
What is judgemental sampling? This technique
depends solely on the knowledge of the archaeologist, whose judgement
indicates areas to sample. If you know that the plaza in front of the
pyramidal mound was usually swept clean of artifacts, you might not
dig there. If builders of burial mounds placed the deposit of exotic
artifacts on the east side, you might place your excavation unit there.
If looters have disturbed the site with their potholes, you might choose
to dig around an old tree with large roots, knowing it will be difficult
but that the cultural deposits will be perhaps less damaged since looters
prefer easy work.
What is the sequence of research for an archaeological project? Your book outlines the process, from research design to implementation to data and materials processing to interpretation and publication [diagram, page 73 of text]. What is the ethical consequence of not following through to publication? You might as well dynamite the site if you have destroyed it through excavation but have no report to show for the work! Your findings need to be available not only to other scientists but to the public who (usually) funded it.
Beyond just methods and techniques, what are the ethical considerations in planning archaeological research, as regards, for example, landowners, the public, the professional community, and funding agencies? All research designs should also require historical background investigation (what has been done on this site and this land before; what historical records do we have?). Another consideration is the obligations to the funding agency. What kinds of reports (technical and popular?) do they require? What kinds of reporting guidelines? Are any research areas sensitive? (For example, everything from dealing with human skeletal remains to working on restricted military lands to using historic personal photos).