Next, we break apart the bars and align them so that all of the same colored bars are positioned vertically next to the others.
A good source of information about how to make charts in Excel is Ted French's Excel Chart Tutorial (for several different versions of Excel).The figure on this page is a Microsoft Excel (TM) table showing the results of our frequency count.Our next step is to create a bar graph of the percentages of the objects in our junkyard samples.The seriation method works because object styles change over time; they always have and always will.A good example of a change in artifact type is the development of hand-held PDAs from those first enormous cell phones. As an example of how change through time works, consider the different music recording methods that were used in the 20th century.The same is true for 45s, and 8-tracks, and cassette tapes, and LPs, and CDs, and DVDs, and mp3 players (and really, any kind of artifact).
For this seriation demonstration, we're going to assume that we know of six junkyards (Junkyards A-F), scattered in the rural areas around our community, all dated to the 20th century.
Seriation, also called artifact sequencing, is an early scientific method of relative dating, invented (most likely) by the Egyptologist Sir William Flinders Petrie in the late 19th century.
Petrie's problem was that he had discovered several predynastic cemeteries along the Nile River in Egypt that seemed to be from the same period, but he needed a way to put them in chronological order.
You would expect a large number in one closed when 78s were popular and a small number again after 78s were replaced by a different technology.
You might find a small number of 78s for a long period after they were pretty much done.
Archaeologically, you would expect no 78s to be found in a junkyard that was closed before 78s were invented.