Anth. 473L/ 573L: Archaeological Measurement and
Laboratory Analysis
Spring 2003
(More Debitage
and Cores)
Exercise 4B is the
continuation of Exercise 4A. In exercise 4A, you performed an item analysis,
examining and coding for attributes of each piece of debitage (Shott 1994;
Steffen et al 1998). The item was the synthetic unit; attributes were the
analytic units. In preparation for completing this exercise, we asked you to
construct a paradigm of the attributes you measured across items and examine
the distribution of classes. Associated with that construction should have been
a series of tables or figures. In this
part of the exercise, you will make further observations of the debitage sample
and also make observations on cores.
For this exercise, you will
need several copies of the debitage coding sheet (more will be provided in the
lab), one copy of the core coding sheet, and your copy of the debitage
protocol.
To reiterate the goals of
this 2-part exercise: First, we want
to give you some hands-on familiarity with archaeological chipped stone
residue. In doing so, the exercise
highlights some of the basic problems encountered in examining chipped stone
collections, e.g., reliably assessing flake dimensions, and reliably
identifying and separating removals from cores. Second, we want to introduce paradigmatic classifications as
research tools. That is, the exercise
provides an example of how paradigms can be used as analytical devices to
partition variation in archaeological collections of objects. Third,
we want you to describe and evaluate variation in core reduction within and
among different raw materials. There is considerable diversity in the size,
type, and mode of reduction of materials on each tray. By making a series of
observations, you will be able to describe some of that variation. After completing this exercise, you should
be able to: (1) distinguish among
cores, flakes and angular debris, (2) define and assess the basic dimensions of
cores and flakes, and (3) construct paradigmatic classifications relevant to
your research interests (4) build preliminary descriptions of variation in
chipped stone residues by raw material.
BASIC
ORGANIZATION OF THIS EXERCISE:
The procedure for 4B has two
parts. For flakes and angular debris,
you will continue the item analysis by coding for one of the two variables
you did not complete (exterior flake scars or platform).
You will also work on an
item-by-item basis with cores (because, after all, cores and removals comprise
the totality of reduction). With cores, you will choose what variables you want
to measure, but the measurements must be related to the goal of describing
reduction. Because you only have a week
to complete this exercise, it is important to make all of your measurements
during your lab period.
STEP ONE: Completion of Coding for debitage
Now
that you have greater familiarity with the diversity of debitage, you should
begin by examining your previous decisions. Were some of the items that you
coded as angular debris possibly flakes?
Did you correctly identify the raw materials? Then decide which of the two additional variables will likely
provide you with more information about the process of reduction in your
sample. Perhaps much of the debitage is
missing platforms. If that is the case,
then coding for platforms will likely not be very productive. Perhaps you want to try to apply Baumler's
grid to the complete flakes in your sample and to orient the direction of
previous flake removals. (Although this was not suggested, you can do it if you
choose. It is likely to be very
time-consuming.) This information and the location of the platform could, in
turn, inform on core form.
Alternatively, you could simply record the number of flake scars on the
exterior surface of complete flakes.
Complete the coding for whatever variable you choose.
STEP TWO:
Coding cores
Make
observations on the cores in your collection.
You will decide what variables are important to record, and record them
using the core coding form. Because you are deciding, your first step is
to create a protocol. Decide on the
variables, and use numbers to identify attribute states for each variable. (Write
this down!) To describe the cores,
you should focus on size, material, on platforms and direction of
removals -- see discussions in Baumler (1988) and Kuhn (1995) for further
discussion of how these variables are relevant to measuring variation in
reduction. Because size is difficult to measure, weight is always a useful
proxy for size. You might note the
number of platforms and their relationships to one another, e.g., opposed
platforms. Also note whether the cores
exhibit unidirectional, bidirectional or multidirectional removals. We suggest
you code for no more than three variables, including weight.
Put the information from
your coding forms into a database/ spreadsheet/ statistical program (Excel should
work well). You should already have a
file from Exercise 4A. The first step
is to enter the new observations on the debitage. Then, on separate worksheet, enter your observations on cores.
Because there are many fewer cores than flakes, this table will be much
smaller. Manipulating these
observations will be the basis for examining membership in your paradigmatic
classes. Below we suggest a number of questions that can be used to query your
data base and to construct appropriate tables and charts. To address the questions, you should
construct appropriate tables and figures (these are your data!!)
Debitage
Analysis, Manipulating Paradigms, and Constructing Data
Create a second paradigm for
your flakes using all five variables (excluding weight), and compare the
results of paradigms 1 and 2 in terms
of the number of classes, and how your debitage sample is distributed across
the classes. N.B. You will not be
able to draw a paradigm with five variables as a table (at least not in any
simple way in two dimensions). Put the
information into your computer program and look at the distribution of
classes. Calculate the number of
classes in the paradigm, count how many classes you have represented in your
sample, and then calculate a ratio of filled to empty classes. Once you have constructed the “master
paradigm”, you can begin to collapse variables in order to address specific
questions (e.g. you can look specifically at the relationship between material
type and weight or material type and number of external surface flake
scars.) Construct tables and charts
that convey this information. These
tables and figures are the basis of your descriptions. Consider whether the addition of another
variable provided more information about the process of reduction. Did the addition create too many classes in
your “master paradigm” such that there are very few items in each class? Consider various ways of collapsing 2
variables into one or removing variables in order to more usefully display the
variation you examined.
When working with debitage
it is useful to consider both counts and weights because they contain different
kinds of information. Obsidian, for
instance may be very abundant, but weight might be 1/100 of basalt debitage
which is represented by fewer but larger pieces. Examine the distribution of items across the classes you create,
considering proportions (percentages) as well as frequencies. Which debitage classes have the most
members? Which raw material type is
represented by the most numbers of flakes? Does this variation change if you
consider both counts and weights? If it
does change, why does it change? Does the proportion of flakes match the
proportion of angular debris by raw material type? Going further, does debitage
vary by size and reduction characteristics?
In other words, is there any tendency for kinds of debitage to vary by
raw material?
Although
the focus of this analysis is on how classes partitioned variation, it might be
useful to consider variation in individual attributes. For example, determine
the proportions of cortical and noncortical flakes or the proportions of flakes
and angular debris for each raw material. In other words, you have two ways to
proceed with the analysis: by class and by single variables. Examining the latter can be extremely useful
for elucidating differences among raw materials.
Core Analysis
First, there are many fewer
cores in your sample than debitage. This fact means that your core classes will
have many fewer items. Nonetheless, we
want you to characterize the diversity of cores through paradigmatic
classes. The first step is to
characterize your cores in terms of classes.
Perhaps you have 3 raw material types represented by cores. If this is the case, then a simple histogram
of weight units by raw material may be an effective way to characterize
cores. Degree of reduction may be
reflected in the differential presence of cortex remaining on the nuclei. Does core size inform on the use life of the
material?
To maximize the information
present on cores, you need to link cores and debitage together. Here, controlling for raw material is
essential. For a given material type,
does size of core relate in a general way to size of flakes? Does the number of core faces relate to number
and direction of exterior flake scars on flakes?
DISCUSSION OF
RESULTS
Excluding tables, figures and coding
forms, your write-up should not exceed 8
pages, and please note which collection you examined. As usual, your discussion should include both
analytic and synthetic components (follow the recommended lab write-up
structure).
First, discuss how the
paradigms sorted the observed variation for both cores and flakes. The
paradigms should be discussed separately; summarize them. How well did the paradigms perform? How did
your classification of cores sort the variation across raw materials--at this
point you should enumerate which variables you used to construct your
classification and give some kind of justification for using them. Second,
evaluate both paradigms of debitage in terms of how they partitioned the
variation, particularly across raw materials. If, for instance, each class
contained a small number of members, then the paradigm was too fine-grained for
the sample. If you collapsed some variables, be sure to describe this and
justify your decisions. Conversely, if a small number of classes contain most
of the specimens, then the paradigm was too coarse-grained for the sample.
Discuss the advantages and disadvantages of paradigmatic classifications for
measuring variation in core reduction.
Did examining the classes allow you to document and examine variation
across raw materials? Lastly, discuss
what you learned about variation in reduction from sorting the collection using
paradigmatic classifications.
Part Two (Measuring Reduction)
While
Part One focuses on evaluating the utility of paradigmatic classifications,
Part Two is concerned with assessing variation in core reduction. Here the
analytic units are the classes you created and variation in core reduction is
the synthetic unit. First, discuss the
documented differences (or lack thereof) in reduction across raw materials. Second, did weight indicate differences
among the raw materials, and did it allow you to evaluate differences observed
relative to formal (nominal) dimensions? Third, did your classification
partition the variation in terms relevant to the goals of your analysis? That is, did your classification allow you
to document differences among raw materials deemed significant for
reduction? Finally, did examination of
the cores assist you in understanding differences in reduction across the raw
materials; in other words, how do the cores and flakes articulate with and
inform on one another?
In
evaluating your results, consider the reliability
and validity of your units. Are the variables used in the analysis valid
measures of reduction? It might be appropriate to consider here Steffen's
(1998) discussion of the difference between technological and functional units.
What reliability issues did you encounter in classifying the debitage? Once again, evaluate your units, to the best of your ability. In 1971 in Systematics in Prehistory, Dunnell
stated: "If the units [classes] are the product of a properly executed
paradigmatic classification--i.e., all possible meanings that any correlations
the units might have are known--they are overtly built into the units. The
application of the units in a practical problem constitutes the testing of the
hypotheses made in the classification." (1971:76). Did you find this to be
the case? Steffen et al. (1998) provide an excellent example of a
paradigm that shows the difference between cores and tools.
CORE
CODING FORM
Name___________ Tray______
|
SPEC
NO. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|