Middle and Late Bronze Age Metal Tools from the Aegean, Eastern ...

kinds of implements are presented in Figure 4.5a. As broad chisels are generally longer,
they have a higher ratio (mean of 5.33) than the other tools. Trunnion blades and
single/flat axes have a comparable ratio (mean of 3.2 and 2.8 respectively), while single
adzes have low ratio mean of 2.3. The adze ratio is skewed and not an accurate reflection
of the tool type, since numerous single adzes in the database came from the Gelidonya
shipwreck and are fragmentary.
Despite the different ratios (as measured by the mean), there are instances of
overlap among the categories. When a tool’s ratio hovers between 3.5 and 4, it could be
classified under any four of the implements. 348 This conclusion is evident when
examining a box-and-dot plot (Figure 4.5b), showing the general range and outliers of a
tool category’s ratio (length divided by cutting width). 349 The box represents the “mid-
spread” of the data—that is the central half of the bunch; the horizontal line in the box is
the median (and not the mean) of the data. The vertical lines on either side of the box are
called “adjacent values” and represent the full extent of the dataset’s range. Small shapes,
on either side of the adjacent values, are used to designate “outliers”; outliers are defined
by their distance from the rest of the data. When the distance between the upper or lower
quartile of a mid-spread is greater than 1.5 times the mid-spread range, then those plots
are designated as outliers. 350
These ratios and box-and-dot plot demonstrate that there are undeniable
similarities in tool size and shape and that length and width measurements may point to
348
This conclusion is similar but slightly different from the 4.4 ratio that McGeehan-Liritzis used to
differentiate chisels from axes from the Late Neolithic and Early Bronze Age Aegean; see McGeehan-
Liritzis 1996, 58-59. As a general rule of thumb, chisels will have higher L:W ratios than axes, but a gray
area certainly exists.
349
Drennan 2009, 37-41; this box-and-dot plot was made using a statistics computer program, PASW
Statistics 18.
350
Drennan 2009, 38-40.
147