BAJR Federation Archaeology

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How do most commercial companies evaluate urban sites with deep stratigraphy? Do they machine dig trenches down to the first 'significant' horizon and then use single context planning/excavation from there onwards (which could take weeks)? Or do they cut the trenches down to the first horizon and then put slots in hoping to get some idea of the depositional sequence and archaeology along the way?

If the latter, how often to urban evals produce misleading results?

Many thanks for any comments.
That is a very good question, and indeed you could say that evals in deep strat do give misleading results. I have one here (pic below) in York, where we dropped in 5 trenches across the site dug everything single context. it gave us a full idea of depth and quality of preservation as well as what to expect... what we did not expect or find in the eval was the buildings, the road, the thousand plus coins arranged around a pillar - the bridge piers, the wooden buildings etc etc................. however, the eval meant you were not going in blind, you had a good idea of depth.. (though once an eval in a castle managed to hit the only bit of bedrock that had a hole 2 m deep! - hence our surprise when we hit the top with a mattock and hit bedrock 25cm down!!) in as much as you can be... we were prepared for organic survival, we knew to expect good Roman and possible Anglian and the rest is history. Eval in deep strat is as valid as elsewhere... I have seen a field full of trenches that manged to miss the archaeology .. (by accident I hope!) round houses and even an 18th C farmhouse.

You have to consider the point of the eval. and never be shocked that the eval does not match the full excavation.... it just prepares you for it
I have seen both methods used as you outline.

Of course one of the advantages that urban archaeologists have is prior knowledge of nearby sites allowing estimation of the likely archaeological deposits dependent upon the extent of truncation. How often does it go wrong? Sometimes, but some/most units specialising in urban archaeology are very experienced and that cuts down on the potential for mistakes.....
Or do they machine all the way to the bottom and draw the section. I think that your best way of looking at evaluations is that no two are the same and that’s the problem with standards/map2/ Evaluation I think is mentioned once in pps5/6 and merely described as an “inexpensive method” in ppg16.

Maybe all so called methods are going on at the same time. Another issue is whether the evaluation should be a lost leader.

What you should be getting at is pricing and profit. What do you mean by how often do evaluations produce misleading results. Do you mean the evaluation made a loss or do you mean that someone else undertook a subsequent excavation which as a result of the evaluation made a loss. I don’t really see how that could happen. Has anybody heard of an evaluation which lead to court action for producing misleading results?
Rather than spout off myself about the range of techniques applied. Why don't you take a look at some of the 5000+ reports lodged in the Archaeology Data Service's Grey Literature library You can search by contractor, but if you go to the main search page and put London in the County box you'll get results for one well known urban area. Similarly putting York in the district/unitary authority box gets quite a few hits too. Happy reading! Smile
Thanks for the responses. I guess this means there is no set approach and each site is treated on an individual basis?

Unitof1: I wasn't really considering this from the perspective of profit and loss (or legal action, though that's an interesting point), just misleading archaeological interpretations that prove to be badly off the mark when the site is fully excavated. There is another side to the profit / loss debate which hinges on this as well: if one company costs for an eval on the basis of single context recording (time consuming, needs lots of staff etc. and therefore costly) and another for putting in a few slots (quicker and cheaper) isn't the latter generally going to win the contract? So, by extension, doesn't that mean that most commercial companies will opt for slot excavation for deeply stratified urban sites? (From the other replies I see some single context evals take place, so perhaps not...).

Is there any agreement out there on the best way to excavate urban evaluation trenches? Is one approach demonstrably better than the other?

Thanks, I will take a look....
Horses for Courses - it takes lots of experience and insight to strike the right balance between (at one extreme) 100% sequential stratigraphic excavation + full single context recording and planning , and (at the other extreme) test slots/interventions/trenches and recording multicontext exposures....

moderatley and deeply stratified archaeological sites are significantly more complex than shallow ones (and quite often contain 'research grade' resources)

therefore local relic and underlying topography is of major relevance...bore holes provide important ground truth for 'overall' depths of anthropogenic deposits and the relationship between inherited and relic geomorphologhy....

focused goals are often important - how significant are the 18th levels/features compared with eg prehistoric ones? with so much potential material available on an urban site, some pragmatism must often be used, and this might be reflected in the techniques used/the level of recording....

some urban excavations are never larger than evaluation trenches anyway (eg footings) - so the potential loss and future unavailability of material must be considered seriously at all stages.

many full excavations show that evaluations have been seriously deficient (not necessarily with blame) in predicting the nature of archaeological remains - however depth of anthropogenic disturbance is generally as expected......
And let us not forget that the clients are really different. It’s a lot easier to make a load of dosh off a consultant led headless chicken government job than a client who has it in their DNA that archaeology is whats missing from a bullock

[SIZE=3]Is one approach demonstrably better than the other?

If you have ?100 of expenses/investment do you expect to make 750% profit before tax

While everybody is hiding from making money out of evaluations I thought that maybe another question that fieldworker might be looking at is the interpretation of an evaluation. This ultimately is the get out that fieldworker that needs to understand and feed back into the perfect how do you do it question

Quote:[SIZE=3]how often to urban evals produce misleading results?

Depends how good you are at interpreting evaluations does it not. Take this piece of string….

Are the interpretations by the end user important-yes and no

this adds to the problem with evaluations is

1) why is there an evaluation in the first place
2) who evaluates the evaluation
3) only then is the archaeologist who undertook the evaluation undertaking the excavation

there are at least three if not four chancers in this play
a) the client
b) the curators
c) the evaluator
d) the excavator

but before taking the great unknown- whats there really there, and the permutaions of the above agents we have to get involved with chicken and egg problems because the consequence that we are leading to is-what is a good Excavation.

Is a good excavation one where the bidder spotted that the evaluation was crap and had totally over sold the archaeology that was there so allowing an outrageous undercutting bid but one that still made 750%
problem is its easy to claim that is/was the case, when curators are so hamstrung...
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