LITHic Analysis of stone tools

 System to identify the type of stone tool  Created ~20 years ago by Roger Grace  Programmed using Macintosh’s Hyperstudio  At the time it was tested by a group of students ◦ The students all came out with similar answers, even when some of the values entered were different

 LITHAN is a set way of identifying tools  Also provides information on ◦ Blank type ( blade, bladelet, flake, chip, fragment or chunk) ◦ Flint knapping Technology ( blade, flake, Levallois) ◦ Hammer mode ( soft or hard ) ◦ Cortex

 Takes 19 different attribute values  Compares these values to the system rules  Produces a screen with the conclusions on it

 Two types of attributes used ◦ Measured ◦ Observed  Measured – values measured, normally using callipers  Observed – observed by the naked eye or using a low power microscope

 7 measured attributes ◦ Tool length ◦ Tool width ◦ Tool thickness ◦ Mid-point width ◦ Mid-point thickness ◦ Platform width ◦ Platform thickness

 12 different observed attributes  These normally have a screen with specific options to select from  These allows only certain values to be entered

◦ Platform type ◦ Lateral edges ◦ Dorsal ridges ◦ Cortex ◦ Percussion ◦ Butt ◦ Bulb ◦ Retouch ◦ Position of retouch ◦ Retouch type ◦ Edge form ◦ End form

 If certain options are entered a screen automatically pops up to clarify observations and help with identification ◦ Platform type = core ◦ Retouch type = burin blow ◦ Tool type = arrowhead ◦ Tool type = microlith

 Cards to clarify options when Platform type = Core

 Cards to clarify when Retouch = Burin Blow

 Card used when Type = arrowhead

 Card used when type = microlith

 LITHAN has ~ 30 pages of programming covering the rules in the system  Has two types of rules ◦ General – applied all the time ◦ Secondary – applied only if a specific conclusion is previously reached

 Rule to determine blank type  If (length/width) > 2 and width < 12 mm  Then Blank type = “Bladelet”  Rule to determine technology  If Platform thickness < 5 and Platform type = “prepared” and Lateral Edges = “parallel” and Dorsal ridges = “parallel”  Then Technology type = “Blade”  Rule to determine hammer mode  If percussion = “no cone” and Butt = “un-lipped” and Bulb = “diffuse”  Then hammer mode = “soft”

 Rule determining type of tool  If (length – width) > 0 and retouch position = “distal”  Then type = “End scraper”  Secondary rule  If type = “End scraper” and End form = “Round”  Then type = “End scraper”  Else if type = “End scraper” and End form = “Carinated”  Then type = “Carinated End Scraper

Functional Analysis of Stone Tools

 Functional Analysis of Stone Tools  Sister program to LITHAN  LITHAN results can be used in the program  FAST uses the information it gathers to determine the wear on an artefact ◦ Wear meaning what sort of material it was used on ◦ e.g.. Fish scale, hide, antler, bone, etc…

 Takes in 20 different attribute values  Uses fuzzy logic to calculate the best possible answer  Each attribute has allowable values which are selected from a new card by the user

 Three types of attributes ◦ Measured ◦ Macro Observed  Observation using low powered magnification ◦ Micro Observed  Observations made under high magnification

 Edge angle  Length  Thickness  Profile  Shape

 Gloss on the Edge wear  Fractures – a count of them  Fracture type  Rounding – is the edge of tool rounded

 Fractures and Fracture Type  Rounding  Micro topography  Distribution  Distribution type  Invasiveness  Linear features  Striations  Polish development

 Some absent values can be used to determine use ◦ E.g.. If the edge is not round, tool was probably used on a softer material  Other values, while present, are not important for the determining of use ◦ E.g.. Micro fractures are not diagnostic because they can occur from any sort of contact motion

 Once attributes are entered they are displayed on two cards ◦ One for the Measured and Macro Observation ◦ One for the Micro Observations

 3 types ◦ General ◦ Fuzzy ◦ Function

 Attributes are used singlely or in combination ◦ E.g.. (edge angle< 30°) then Angle = ‘cutting soft material’ ◦ E.g.. (fractures = ‘absent’) and (edge angle > 30 and <60) then Angle = ‘medium material’  Conclusions reached by the rules are Observations  This Observations are then used in the Fuzzy Rules

 The fuzzy rules use the conclusions from the general rules  Each conclusion have specific numerical value placed on them according to the rules  The values are totaled to produce a score value  The score value is used in the function rules

 Each variable (egg. Angle, length, profile) count as 2 (see the Macro Card)  If the surfaces’ (Ventral/Dorsal) have values the add 0.5 ◦ Unless “retouch”, “no polish”, or “no effect” Then add 1 – because they are more telling  ‘Non-Diagnostic’ = 0  All motion scores (except rotational) are doubled

 Use the Score values to determine ◦ Function ◦ Hardness of material ◦ Type of Material

 Function ◦ E.g.. ‘cutting’ 8 and ‘grooving’ <2 and ‘whittling’ < 2 then function = ‘scraping’  Hardness ◦ E.g.. (‘soft’ > 4 and 0 and < 2) and ‘hard = 0’ then hardness = ‘soft’  Type ◦ E.g.. ‘soft’ 5 and ‘hard’ = 0 then type = ‘wood’  Type can also have more complex rules involving motion, and other values

 Results are displayed on a single screen  If unable to determine a value then ‘Insufficient Data’ is displayed  Occurs in 2 cases normally ◦ Not enough use wear on tool ◦ Use wear not consist with a specific use

 LITHAN determines type of tool  The value found by LITHAN and be put into the FAST system  FAST finds the use of the tool  Both systems tested at Universities  FAST has a 90% success rate during tests  LITHAN tests have users coming up with the same answers – even when some value are different for the same tool

 Rules are cemented and written down  Different people will still get the same values

 If rule is determined to be incorrect (e.g. Value given more weight then it should have) all findings have to be suspect

 Different people will get the same result ◦ Allows comparison without worry of results being different because of the typologist  LITHAN does not use Fuzzy Logic so the answers it provides are presumed accurate ◦ If not enough information is provided (i.e.. Because tool is broken or pieces are missing) then the value is designated “indeterminate”  Can update as new rules are found  Records the tool type into a permanent record

 Does not provide a great deal of useful information ◦ So it’s a scraper/arrowhead/other tool, big deal, most past societies have these  Most of the conclusions can be drawn from eye sight

 Runs a complex analysis quickly once values entered  Information is relevant to research ◦ E.g.. Scraping hide implies hunting

 Uses fuzzy logic, so have to be aware the answer is weighted

 When designing the programs the creator had to think about three things ◦ Facts to include ◦ Rules to include ◦ Storage of solutions

 The facts ◦ all contribute to the solution (e.g. colour of tool – tells nothing of type or use of tool) ◦ If too few – no accurate answer gained ◦ If too many – spend so much time entering data, easier to do it by hand

 The rules ◦ if wrong or too vague then the system does not provide an accurate answer ◦ Have to provide for all possible cases ◦ Must be updated if new information gained (e.g. FAST has a lot of information about use wear as it is applied to fish scales because it was used in a Norwegian study that had fish scale wear on tools)  Storage ◦ Have to store answers for reference ◦ Don’t want storage to be hard to search ◦ Both LITHAN and FAST use Hypercard for this

 LITHAN is a system that is useful in a limited area  Helps with the consistency of identification of tools  FAST is a system with a wider range of usefulness  LITHAN while interesting is not helpful, other than in a data gathering way – like a database  FAST provides important information and shows the reasoning behind a complicated process  If the program the systems are written on was updated the programs would be more useful

 LITHAN and FAST use some of the same attributes ◦ LITHAN has more in depth measurements of tool ◦ FAST has micro observations  Might combine the 2 programs to run as one ◦ LITHAN has a limited value, FAST is more useful for studies ◦ Would require the reworking of the rules

 LITHAN Movie by Roger Grace ◦  LITHAN; Grace, Roger ◦ ic/expsys.html#anchor  FAST; Grace, Roger ◦ ic/FAST.html