[WEEKENDER] A day with Jerry, guide dog in training

As Jerry, a Labrador retriever, approached a crosswalk, he came to a stop at the curb. His trainer, Keum Jung-hun, had given no command. Jerry simply recognized the boundary between the sidewalk and the road and stopped on his own. Keum pressed a small device, producing a sharp click. Known as a clicker, the tool signals that Jerry has performed…