I was taught not to approach strangers out of friendliness or otherwise, but if I was in SERIOUS help, then it would be a good idea, esp. if I couldn’t call 911. Children have a tough time with ambiguity when they are young. I think it’s best to teach them when they are REALLY young to stay away from strangers…when they are that young, it’s highly unlikely they’d be out on their own! However, when they are a older and are out playing unsupervised (which is normal, I used to bike everywhere by myself, no cell phone), then you can modify the stranger rule.