Russel-Research-Method-in-Anthropology

Multivariate Analysis 687
1.71
1.32
GRAPEFRUIT
LEMON
ORANGE
0.94
0.55
0.17
-0.22
CANTELOPE
STRAWBERRY
WATERMELON
BLUEBERRY
PLUM
APPLE FIG
PEACH
CHERRY
PEAR
-0.60
-0.98
MANGO
PAPAYA
PINEAPPLE
BANANA
-1.37
AVOCADO
-1.75
-2.14
-2.14 -1.37 -0.60 0.17 0.94 1.71
Figure 21.5. Two-dimensional MDS for 18 fruits sorted by one informant.
mant sees the similarities among these 18 fruits. It is, in other words, a mental
map. Make no mistake here. The MDS graph is simply a representation of
what the informant was thinking when he pile sorted those fruits. No one
claims that MDS graphs are one-for-one maps of what’s happening inside
people’s heads.
Now, suppose we collect a whole set of pile sort data from, say, 20 informants.
That would produce 20 individual similarity matrices. If we stacked
those matrices on top of one another we could look down through each cell,
count up the number of 1s, and divide by 20. That would tell us the percentage
of times that the 20 informants put a pair of items (fruits, for example)
together in a pile. This would create an aggregate proximity matrix—a summary
of percentages, rather than just hits, that tell us how similar, on average