Should the Y-axis always be zero in graphs?
This is good post though unfortunately a bit misleading in my opinion. Excel often sets the Y-Axis to something non-zero. Thus although at times it is okay, many without statistical knowledge just use the default.
Yes a picture is worth a thousand words and if made properly can be very informative. If made to just look nice without enough though it can be very misleading. I like having the numbers with the graph to let the reader decide ultimately.
Finally, a note for students. Don't be lazy, think about the graph and what it says. Does it say what you want? Some of my thoughts is that of a professor, as I see tons of people making graphs without thought as to the story.
Well enjoy the video.