Hi, can anyone help?
I am trying to run Wards hierarchical cluster analysis on a set of
binary variables using Jaccards coefficient as a measure of similarity,
however SPSS is failing to run the clustering because it is saying there
are too many missing distances in the proximity matrix?
Warnings
WEIGHT command is currently in effect. This command is ignored by
CLUSTER.
The squared Euclidean measure should be used when the CENTROID, MEDIAN,
or WARD cluster method is requested.
The proximity matrix contains too many missing distances. CLUSTER
procedure cannot continue.
This command is not executed.
Can anyone tell me why this would be the case? We thought that it might
be because there weren't many respondents who shared the trait of
interest or indeed have the trait of interest so we would end up with a
denominator = 0?
Jaccard's coefficient = a / (a + b + c), so a+b+c = 0.
Based on the table below
Respondent 2
Respondent 1 1 0
1 a b
0 c d
Thanks
Jamie
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