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Sometimes less is more

Sometimes less is more. Comparison of rapid and traditional recording methods Bantycock Mine, Balderton. Recording methods. Traditional – record everything, including ‘Unidentified’ and ‘-Sized’ Rapid – diagnostic zone system, records limited pre-defined set:.

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Sometimes less is more

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  1. Sometimes less is more Comparison of rapid and traditional recording methods Bantycock Mine, Balderton

  2. Recording methods • Traditional– record everything, including ‘Unidentified’ and ‘-Sized’ • Rapid– diagnostic zone system, records limited pre-defined set: • 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

  3. 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 ?

  4. 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)

  5. Evaluation of recording & quantification method • Richardson’s original method recorded all specimens, but also identified ‘diagnostic zones’ • Thusrapid 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 • Original report • All specimens • Rapid Zones • Zones

  6. 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

  7. Rapid Zone Method Recording & Zone Criteria • 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

  8. Method summary • Original Method • Rapid Zone Method • 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 • All material recorded • Zones: • 34 post cranial zones • 2 teeth • 38 post-cranial Measurements

  9. 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

  10. Recording comparison Total Recorded Material • Both in MS Access Database • Original Method • Rapid Zone Method • 5000 + more specimens • ~ 800 more measurements

  11. Quantification comparison Absolute Frequency • Original Method • Rapid Zone Method NISP –number ofidentified specimens Zone count –number of zones More material recorded than counted • Instead of NISP useNCSP –number of counted specimens • NISP = 6965 • NCSP = 1218.5 • Zone Count = 1498 • Includes ‘animal-sized’ material • Only 2 teeth • Includes all teeth

  12. n = Original zones – Rapid zones Absolute Frequency Difference in zone count More in Original Zones More in Rapid Zones

  13. Different zone criteria emphasize different body parts Absolute Frequency Difference in zone count • Original Zone Method • Rapid Zone Method • 3 zones on limb shafts • Only 2 teeth • 1 zone per bone • All teeth • Hypothesized Biases • Bias against animalsnot eaten (no dP4s) • Bias toward animals with less-fragmented limbs zones (smaller) • Fragmentation bias more equal: only 1 zone per bone • More conservative system better describes recorded material

  14. Relative Frequency Common taxa • CATTLE SHEEP/GOAT PIG • Relative Frequency • Rapid Method • NCSP • Original NISP • Original Zones

  15. Relative Frequency Common taxa • CATTLE SHEEP/GOAT PIG • Relative Frequency • Rapid Method • NCSP • DIFFERENCEin relative frequencies (Original – NCSP) • Original NISP • Original Zones

  16. 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

  17. Body part distribution • Original reportdid 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 skeletonfairly evenly represented • MAU like MNI but doesn’t involve side = total for element / 2 • Because of shaft anxiety – look at how shafts are represented…

  18. Original Number of Limb Bone Zones • MAU 4.5 • MAU 3 • Total • MAU • 4 • 7 • 6 • 4 • 6

  19. Original Number of Limb Bone Zones • MAU 4 • MAU 5 • MAU 3 • MAU 3 • MAU 6 • Total • MAU • 4 • 3 • 15 • 3 • 4

  20. 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

  21. 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.

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