Even though we didn't use the portable potty like Hannah (we used the potty seat on toilet), this book make everything click for our daughter. She wanted be a "big girl" just like Hannah. We tried 3 or 4 other books without success. The timing was helpful too because a month after we introduced potty training, we moved our daughter to the "big girl" bed so it was a consistent theme. 3 weeks later we gave up diapers during the day, then naptime diapers went away about 3-4 weeks later. We have lots of excess diapers now, but well worth it!Terrific book for potty training.