Not sure what mathmatical route to take

#1
I am trying to compare the quantities and types of stone artifacts between four different archaeological excavation units from one archaeological site. While all units are 1 m. by 1 m., each excavation unit has been dug to different depths. How can I compare each unit's number & percentage of artifacts by type when each unit varies by depth and subsequently by amounts of excavated earth? Basically, I am trying to see if any differences in artifact quantities and percentages are significant or if the quantative differences are because of the size sample. Help Please!

Thanks,
Kim:wave:
 

JohnM

TS Contributor
#2
Could you standardize each unit's archeological "find" by dividing the quantity by the size of the corresponding dig? That might help you make comparisons....
 

JohnM

TS Contributor
#4
Relative frequency of ........?

The way I'm looking at it (maybe I'm over-simplifying it?) there are 4 excavation units, each having a quantity and variety of stone artifacts. To avoid comparing apples to oranges, let's say the following data is available (fictional):

Unit------Depth--------Quantity
1---------100------------10
2---------220------------6
3---------175------------11
4---------235------------10

For each unit, divide quantity by depth to get an artifact "rate"

10/100 = 0.100
6/220 = 0.027
11/175 = 0.063
10/235 = 0.043

Even though unit 1 is "tied" for second place in terms of quantity, its yield per foot of digging is the highest....
 
#5
Thanks, here's some other feedback that was also helpful

You are interested in the DENSITY of artifacts, i.e., how many artifacts
per cubic meter of matrix.

Let's say you have a 20 cm-thick level. THen you have .2 cubic meters of
dirt (1 m x 1m x .2 m = .2 m3) If there are 22 artifacts in it, the
density is 22 artifacts/.2m3 earth = 110 artifacts/m3.

If you have a level that has 64 artifacts and is 40 cm thick, the density
is: 64/(1 x 1 x .4) = 64/.4 = 640/4 = 160 artifacts/m3.

*DON'T* divide percents this way. Just look at raw numbers.

--The previous comment was very close