Issue about mAP

[ericxian1997]

It seems that values of rank1 and mAP produced by state-of-the-art methods on CUHK03 are very close (some method's mAP are even higher than rank-1 accuracy). But on other datasets such as Market-1501 and DukeMTMC-reID, mAP is usually 10％~15％ lower than rank-1 accuracy.
What is the reason for higher mAP on CUHK03?
I use the evaluation code to test my model trained on CUHK03, the mAP is also 10％~15％ lower than rank-1 accuracy, which is inconsistent with the values reported.

[zhunzhong07]

In the CUHK03 new protocol, there have few ground truth images for each identity so that the mAP will be close to the rank-1 accuracy. Did you use the new setting in the evaluation of your model?