No person, place, or thing can capture the attention of a class of sixth graders like "man's best friend." To prompt students' interest in a series of lessons on proportional relationships, the authors brought in a unique teaching aid--a dog. A family dog was used to supply the measurements for scatter plots and variables so that students could explore relationships among data sets--not to mention paws and tails. Students used dog data and scatter plot applets to explore various relationships in a lesson called Canine Conjectures. A visit by a live dog provided the motivation, while electronic technologies allowed data to be efficiently processed, freeing students to focus on reasoning, observing patterns, decision making, and problem solving. (Contains 5 figures.)