Dear All,
A researcher recently asked me to analyse the following data:
Area Str 1999 2000 2001
1 1 1 1 0
1 2 0 0 0
1 3 0 0 0
1 4 3 2 0
1 5 0 0 0
1 6 0 0 0
1 7 0 0 0
1 8 0 0 0
1 9 0 0 0
1 10 1 6 2
1 11 0 0 0
1 12 0 0 0
1 13 0 0 0
1 14 1 0 0
1 15 4 3 5
1 16 0 0 0
1 17 0 2 3
1 18 0 0 0
2 1 0 0 0
2 2 0 0 0
2 3 0 0 0
2 4 0 0 0
2 5 0 0 0
2 6 0 0 0
2 7 0 0 0
2 8 0 0 0
2 9 0 0 0
2 10 0 0 0
2 11 0 0 0
2 12 0 0 0
2 13 0 0 0
2 14 1 2 0
2 15 0 0 1
2 16 0 0 0
2 17 0 0 0
2 18 0 0 0
3 1 0 0 0
3 2 0 0 0
3 3 0 0 0
3 4 0 0 0
3 5 0 1 1
3 6 0 0 0
3 7 0 1 0
3 8 0 0 0
3 9 1 0 0
3 10 0 0 0
3 11 0 0 0
3 12 0 0 0
3 13 0 1 0
3 14 1 0 1
3 15 1 1 1
3 16 0 0 0
3 17 1 0 0
3 18 0 0 0
4 1 0 1 1
4 2 0 1 0
4 3 0 0 0
4 4 2 1 0
4 5 0 0 0
4 6 1 0 0
4 7 0 0 0
4 8 0 2 3
4 9 0 1 0
4 10 0 0 0
4 11 0 1 0
4 12 0 0 0
4 13 0 0 0
4 14 0 0 0
4 15 2 1 3
4 16 0 0 1
4 17 2 3 0
4 18 0 0 0
e.g. Area 1 had one occurrence of Str 1 in year 1999 and 2000 but 0 in
2001.
Samples of animals with a particular disease are sent to a lab for
testing. The disease can take one of a number of forms or strains and
this is determined at the lab. Some strains are more prevalent in
certain areas of the country than others (hence the need for
stratification by area?). What he is interested in is testing the
hypothesis of no difference in the distribution of strains between
years. Any thoughts or help would be much appreciated.
Alan Gordon.
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