How To Compare Apples & Oranges
Use this simple comparison tool to, uhh, compare stuff.
Here’s what I woke up thinking about at 4AM this morning:
When faced with the choice between an apple and an orange — or any number of somewhat dissimilar options — what simple algorithm might be used to facilitate a rational decision?
(Weird, right? It’s just the way my brain works. Be glad you’re you.)
As an example, say you’re on a road trip. You’re the driver and it’s time for a snack. Here are your options:
Assuming you only get to pick one snack, how might you consider which is best? Well, I’m happy to say, I’ve figured it out!*
Step One — Establish Criteria
We must first decide what attributes are important. In this context (driving a car) I’ve come up with the following criteria:
- Tasty — I definitely want to eat something I like.
- Lack of Preparation — Because I need hands on the wheel; eyes on the road.
- Easy to Eat — Same as above. Plus, I don’t want to get yucky.
- Tidiness — I don’t want crumbs all over or food spilling between the seat and the console.
- Healthy — There’s no sense gaining a few more pounds before I get to my destination!
Step Two — Assign Weights
In any decision, some criteria are more important than others, so let’s rank them. To keep things simple, we’ll use a three-point scale and the following rule:
Total the number of your criteria, then distribute that number as “preference points” — zero, one or two — to each of the criteria, where
- “2” means it’s very important
- “1” means it’s somewhat important
- “0” means it’s of little importance.
(You must use all the points.)
With a total of five Snack criteria, here’s how I rated mine:
- Tasty = 2 (This is the most important attribute!)
- Lacks Prep = 1
- Easy to Eat = 1
- Tidiness = 0 (This is least important; I can tidy up the car when I get there.)
- Healthy = 1
Step Three — Score Each Option
Our goal is to assess each option’s rating across our criteria — both positively and negatively — and pick the one that rates highest overall. To do that we’ll begin with a neutral baseline of “average” and determine whether each option exceeds or falls short for the various criteria. Here’s how.
For each option:
- Draw a horizontal line and write your weighted criteria above it.
- Rate each criterion by placing an “x” above, on or below the line, where:
Above = Positive — The option rates above average for this criteria.
On = Neutral — The option rates about average.
Below = Negative — The option rates below average.
- Eliminate any “deal breakers” — options that fall “below the line” for criteria with a weight of 2. (There’s no point in considering options that fail to meet your most desired criteria.)
- Multiply by each criterion’s weight to score each rating:
If the “x” is above the line, multiply the criterion’s weight by +1.
If it’s on the line, multiply the criterion’s weight by 0.
If it’s below the line, multiply the criterion’s weight by -1.
- Lastly, sum the scores for the option’s Total Score.
Here’s how my snack comparison added up, starting with the apple:
- I love apples, so Tasty scores 2 points.
(Tasty weight of 2 multiplied by positive rating of 1)
- They need no Preparation, so 1 point here.
(Prep weight of 1 multiplied by positive rating of 1)
- Apples are Easy to eat, but they can get a little sticky down at the core, so I gave it a neutral rating for this criterion; 0 points.
(Easy weight of 1 multiplied by neutral rating of 0)
- As for Tidiness, I can throw the core out the window (into the tall grass, where bugs will eat it) and avoid messing up my car, but this criterion had a weight of 0, so no points here.
- An apple a day keeps the doctor away. One more point for Healthy.
As you can see, the apple gets a Total Score of 4. Now how about the rest?
Step Four — Highest Score Wins!
You can now compare the totals and determine which choice is the best match for the criteria you care about most. In the example above, Grapes win with a perfect score!
Use the following hierarchy if the score is tied:
- Whichever option presented the most “2s”
- Whichever option had the fewest “-1s”
- If you have more than one criterion with a “2” weight, determine a “super criterion” and select the option that exceeds therein.
- Still can’t decide? Just flip a coin; statistically speaking, it might be your best solution.
Now You Know
So, the next time somebody scoffs at the ability to compare apples and oranges, you can say with confidence: “I know how to do that!”
* Disclaimer: I’m not totally sure this is my invention (after all, algorithms have been around since1600 BC), but it’s a lot more productive than counting sheep.
Originally published at www.dangerouskitchen.com on March 16, 2016.