Expert observers

Correlation coefficient

Brown count

Blue count

Observer 1 vs Observer 2

0.987

0.969

Observer 1 vs Observer 3

0.953

0.807

Observer 1 vs Observer 4

0.965

0.806

Observer 2 vs Observer 3

0.959

0.968

Observer 2 vs Observer 4

0.965

0.806

Observer 3 vs Observer 4

0.977

0.973