Sometimes less is moreComparison of rapid and traditional recording methods

Bantycock Mine, Balderton

Recording methods

Easily identifiable and non-reproducible parts

• Like epiphyses

• Excludes ribs, vertebrae, limb shaft fragments, etc.

• Saves time by recording fraction of excavated assemblage

• Developed by Watson (1979) because NISP highly susceptible to specimen fragmentation & interdependency (one bone counts once)

Reason for comparison: Worry that important information will be lost if entire assemblage not recorded

Traditional – record everything, including ‘Unidentified’ and ‘-Sized’

Rapid – diagnostic zone system, records limited pre-defined set:

Background: Shaft anxiety

Examples have shown rapid methods can be problematic:

• Some Paleolithic sites: Intense bone processing and carnivore gnawing can selectively remove limb bone epiphyses (which are zones)

• Meaty limb bones appear absent because epiphyses missing and limb shafts not counted

• If absence not recognized as artifact of method = incorrect interpretation of human economy, hence anxiety

Rapid methods not appropriate for every research question, but

But can they be confidently applied to English commercialassemblage and effectively address changes in animal husbandry ?

Evaluation of recording & quantification method

• To evaluate methods re-recorded and re-quantified assemblage second time:

Bantycock Mine, Balderton, Newark, Notthinghamshire

• Commercially Excavated by Pre-Construct Archaeology, Lincoln

• Faunal Report by J. Richardson (2008), Archaeological Services WYAS

Bantycock Mine

Gypsum Mine

Chronological periods

Iron Age

Early Roman

Early 2nd to mid/late 4th century AD

mid 4th century or later

Unknown (nearly ¼ assemblage)

Evaluation of recording & quantification method

Richardson’s original method recorded all specimens, but also identified ‘diagnostic zones’

Thus rapid system can be compared to 2 levels to the original report:

1) Evaluate value of recording all specimens

2) Investigate affect of different zone criteria on analysis

ALL SPECIMENS

ZONESRAPID ZONES

ORIGINAL REPORT

ORIGINAL METHOD Recording & Zone Criteria

• All material recorded, including unidentified and indeterminate

• 38 post-cranial measurements & basic aging and sex data

Zones

• 34 post cranial zones

• 3 zones on each limb bone

• 2 teeth

Recording & Zone CriteriaRAPID ZONE METHOD

• Only specimens with zones are recorded (with exception)

• 57 post-cranial measurements + tooth measurements

• Presence or absence of ribs/vertebrae

Zones

Present/absent

Not counted – proximal epiphyses

Method summary

• All material recorded

• Zones:

• 34 post cranial zones

• 2 teeth

• 38 post-cranial Measurements

• Only material with zones is recorded:

• 22 post-cranial zones

• all teeth

• zones on prox. epiphyses not included in quantification

• 57 post-cranial measurements and tooth measurements

ORIGINAL METHOD RAPID ZONE METHOD

Evaluation of recording & quantification method

Comparison:

• Total amount of specimens recorded (Time)

• Total number of measurements recorded (useful information)

• Taxa absolute frequency & relative frequency

• Body part distribution

• Age and sex data

Recording comparison Total Recorded Material

5000 + more specimens ~ 800 more measurements

ORIGINAL METHOD RAPID ZONE METHOD

Both in MS Access Database

Quantification comparison Absolute Frequency

ORIGINAL METHOD RAPID ZONE METHOD

NISP – number of identified specimens

Zone count – number of zones

More material recorded than counted

Instead of NISP use NCSP –number of counted specimens

NISP = 6965NCSP = 1218.5

Includes ‘animal-sized’ material

Only 2 teeth

Includes all teeth

ZONE COUNT = 1498

n = Original zones – Rapid zones

More in Rapid Zones

More in Original Zones

Absolute Frequency Difference in zone count

Different zone criteria emphasize different body parts

Absolute Frequency Difference in zone count

• 3 zones on limb shafts

• Only 2 teeth

ORIGINAL ZONE METHOD RAPID ZONE METHOD

• 1 zone per bone

• All teeth

HYPOTHESIZED BIASES

Fragmentation bias more equal: only 1 zone per bone

More conservative system better describes recorded material

Bias against animals not eaten (no dP4s)

Bias toward animals with less-fragmented limbs zones (smaller)

Relative Frequency Common taxa

Iron Age (153.5)

Early Roman (158.5)

Early 2nd to mid/late4th century (319.5)

Mid-4th century or later (100)

Unphased(246)

010203040506070

%

Relative Frequency

Rapid MethodNCSP

CATTLE SHEEP/GOAT PIG

Original NISP

Iron Age (375)

Early Roman(482)

Early 2nd to mid/late4th century (946)

Mid-4th century or later (261)

Unphased(615)

0

20

40

60

80

%

Original Zones

Iron Age (153)

Early Roman(181)

Early 2nd to mid/late

4th century (346)

Mid-4th century or later (117)

Unphased(288)

0

20

40

60

%

Relative Frequency Common taxa

Iron Age (153.5)

Early Roman (158.5)

Early 2nd to mid/late4th century (319.5)

Mid-4th century or later (100)

Unphased(246)

010203040506070

%

Relative Frequency

Rapid MethodNCSP

-20

-10

0

10

20

dif

fere

nc

e

Original Zones

Original NISP

-20

-10

0

10

20

dif

fere

nc

e

DIFFERENCE in relative frequencies (Original – NCSP)

CATTLE SHEEP/GOAT PIG

Absolute & relative frequency summary

•Relative frequency both systems generally very similar

• Relative frequency from Original NISP most different

• Zone methods show small difference across Iron Age – Roman transition

• Rapid system is more conservative in counting absolute frequency with 1 zone per bone and all teeth

• Better description of assemblage

Body part distribution

• Original report did not quantify body part distribution, but noted that no element was over or underrepresented

• Rapid method quantified MAU (minimum animal units) for domestic taxa by period, also found entire skeleton fairly evenly represented

• MAU like MNI but doesn’t involve side = total for element / 2

Because of shaft anxiety – look at how shafts are represented…

Original Number of Limb Bone Zones

Total MAU 4 7 6 4 6

MAU 3

MAU 4.5

Total MAU 4 3 15 3 4

Original Number of Limb Bone Zones

MAU 4

MAU 6

MAU 5

MAU 3

MAU 3

Body part distribution summary

• Both systems concluded near equal skeletal part distribution

• Closer investigation of limb shaft fragments indicates some bones (radius) may be missed in rapid system

• But not to a significant degree – and if included simply reinforces equal skeletal part distribution

Age and Sex Data• Highly similar in both systems since each records fusion and tooth wear

Comparison summary

At Bantycock:

No significant loss of useful data on species representation, body part distribution, or age and sex data

But Rapid method is faster, has more measurements and better controls for interdependency (point of zones).

In analysis, the problem is not that information is missing, but not knowing what information is missing.

Strength of Rapid methods is accurately describing what material is recorded.

Therefore the method of recording used should be based on its ability to effectively answer research question in time available.