Monday, October 25, 2010

Dog Eats Book: A domestic application of the scientific method

[July 19, 2013: Now a teacher resource at Understanding Science

We had been on a bike ride to our favorite burger joint and as soon as we opened our apartment door, we knew something was off.
Both dogs—Elroy and Murphy—usually greet us with varying degrees of affection, depending on how sleepy they are and depending on how long we’ve been away.

They express themselves by vocalizing, swishing their tails, jumping up with their forepaws, licking our hands or our faces if we bend down, and sniffing our legs and shoes. But this time, although Elroy was as hyper as ever, Murphy held back, sat down, pressed back her ears pulling her face with them, and hung her head as she stared up at us, weakly wagging the tip of her tail.

She looked guilty.

And her mopey expression was reminiscent of the Great Goose Down Throwdown of 2005 (see photo).

Something was definitely up. So we reluctantly hunted around for evidence of destruction and quickly found it.

The book that Kevin just bought yesterday was naked, the punctured jacket strewn in the corner, the back cover was chewed, and the front cover had two puncture holes. When the jacket is placed back onto the book, the holes line up.

"Who did this?" Yes, we actually asked our dogs, trying not to smile or laugh and accidentally reward anyone.

We decided to get to the bottom of this. Of course we don’t want to punish the guilty party; that’s not effective and we’re not mad. The book’s still readable and even if it wasn’t, it’s just a book. We’re just curious about who shreds magazines, sucks on dish towels, rips twenty dollar bills in half and eats half, etc. when we’re not home and we hope to maybe someday figure out how to stop this behavior. Because we've witnessed Murphy wilt in the presence of Elroy's criminal behavior, we couldn't assume that her emotions were betraying her own crime.

So who dunnit? This chewed up book gave us an opportunity to find out which dog was the perpetrator, at least for this particular caper.

And thanks to the SCIENTIFIC METHOD, we can find out who the culprit is!

Who chewed up Kevin’s book?

Theoretical Orientation - Any biases and a logical, testable, reasonable model(s).
We assume that nothing supernatural is to blame for the maiming of the book. No ghosts or werewolves attacked the book. The book did not bite itself. We exclude the possibility that an intruder broke into our house, terrorized one book on Kevin’s nightstand, touched nothing else, and left without leaving a trace of his/her presence. Since there were two live animals with sharp teeth in the house, we assume either of the two animals are responsible and not an intruding animal with sharp teeth from outside.

Hypotheses - Falsifiable predictions generated from the theory. All possible, testable answers to our question.
Hypothesis 1: We cannot say whether it was Murphy or Elroy who destroyed the book.
Hypothesis 2: Elroy did it.
Hypothesis 3: Murphy did it.

Operationalized Hy
potheses - The “recipe” that describes measurement, experiment, observation and how another could replicate the process.
Materials: A measuring device (ruler), the book, Elroy's teeth, Murphy's teeth.

Methods: Measure the distance between the upper and lower canines on both Elroy and Murphy. Measure the distance between the puncture holes on the book.

Hypothesis 1: None of the dog tooth measures match the puncture hole measure. (We cannot say whether it was Murphy or Elroy who destroyed the book.)

Hypothesis 2:
The distance between Elroy's upper or lower canines is the same as the distance between the puncture holes in the book. (Elroy did it.)

Hypothesis 3:
The distance between Murphy's upper or lower canines is the same as the distance between the puncture holes in the book. (Murphy did it.)

Data Collection - In the laboratory, field, library, kitchen, …
Elroy upper canine distance - 4.5 cm
Elroy lower canine distance - 4 cm
Murphy upper canine distance - 3.8 cm
Murphy lower canine distance - 3.5 cm
Distance between puncture holes in book - 3.5 cm

Conclusions - These should be cautiously limited because they are only based on the above steps.
Hypothesis 3 is supported (and Hypothesis 1 is not) because Murphy's canine-to-canine distance matches the distance between the puncture holes. Hypothesis 2 (Elroy did it) is not supported because canines that are further apart than 3.5 cm could not have made the holes and Elroy's are further apart.

Based on the distance between canines, we conclude that Murphy and not Elroy attacked Kevin’s book.

Further evidence is needed to determine whether Murphy also chewed up the back cover. However, we predict that if that evidence were available it would implicate Murphy as well. But, because our study focused on canine-to-canine distance, we can only conclude that Murphy made the puncture holes on the front cover.

Repeat/Replicate or Revise Theory
To affirm our conclusions we would have multiple measures, repeated by multiple observers, including perhaps a digitized computer observer. We could also recreate the book destruction by offering books to each dog, having them chew them up, and studying the remains. That could verify and distinguish Murphy's destruction patterns from Elroy's. However, we are satisfied with our study and our results and will not continue to further humiliate Murphy. We will apply these data to evaluate any future puncture holes. We could also use this study to launch a new one into the exhibition of guilt and guilty emotions in dogs!

In no way did our study suggest a revision of our theoretical orientation (i.e. natural, domestic causes versus supernatural forces or intruders). However, we cannot claim that our study falsifies the possibility that either supernatural forces or weird intruders had it in for Kevin’s book.

On the other hand, our study and our application of the scientific method deemed those untestable notions unnecessary.

And there you have it. What would we do without the scientific method?

Elroy is thrilled to be exonerated...


occamseraser said...

You should send this to PLoS ONE ASAP! ;)

chew e. d.

KJ said...


Jennifer said...

you know how sometimes when parents catch a kid smoking they make them smoke until they are sick? Maybe if you forces Murphy to eat books until he couldn't stand it anymore?

Anonymous said...

I love this! Wish I could use it to illustrate the scientific method in my class. Holly, you are a brilliant writer!

Holly Dunsworth said...

Thanks everybody for the uplifting comments and for not dogging me and Kevin about how we spend our Sunday afternoons :).


Feel free to use this story in your classrooms. No need to cite me (but you can if you want to). Feel free to fib a little and switch the characters to you and your own pets!

Send me an email at the link in my bio (above)if you'd like me to send you a PowerPoint slide show of this lesson on how we use the scientific method to study the past.


Geoffrey Vasile said...

Absolutely awesome. If the teeth don't fit - you must acquit. I was also incredibly pleased to find out that Elroy's nickname is beefstu.

James Goetz said...

Awesome story. And your use of the ruler ended up much cheaper than extracting DNA samples from your dogs and the chewed book.:)

hedgehog said...

This is great, Holly! I should disseminate this to a "wider audience"...especially to those who were at the tiger talk the other day :)

Nickname unavailable said...

Love it! Hilarious and also brilliantly written! The topic especially interests me given my experiences with my own destructive Murphy dog. Our cat Slate is also guilty of stealing food, but it's pretty easy to tell the difference between their dog vs. cat styles. :-)

Holly Dunsworth said...

No need for such elaborate data collection here:

ScienceEgg said...

This would have been a very different outcome if it had involved my chihuahua and a bar of dairy milk chocolate. Very little evidence left apart from shredded tinfoil.

Loved this.