Count Cells With a Ready-Made Model and Check It by Hand
Run Cellpose, a free pretrained cell-segmentation model, on a public microscopy image on your own laptop. Check its outlines by eye, compare its count with your own count of one region, and learn the signals that tell you not to trust a count before it goes into your notebook.
Outcome: A segmented image plus a manual-vs-model count on one region, with your counting rule and one sentence on where the model failed; it passes when a labmate can recount the same region with your rule and get your manual number.