Why Statisticians Avoid the Express Lane
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Transcript of Why Statisticians Avoid the Express Lane
TruckeeChamber.com
TTCTV.org
NewLeaders.com ClearCapital.com
HollandHart.com
UsePayIt.com
Sponsors
Community Partners
TahoeDonner.com/pizza-on-the-hill
Why Statisticians Avoid the Express Lane
Will Kurt
Statistical analysis of why it is possibly preferable to choose
a regular lane over the “express” lane when certain
conditions apply, given that the assumptions of our model
hold.
Who am I?
Data Scientist at Quick Sprout
Blog at CountBayesie.com
Author Learn Haskell (https://www.manning.com/books/learn-haskell)
Factors we need to consider?
Number of People in each line (known/observable)
Number of Items
Time per item
Time per person
Key issue:
Time per person >> Time per item
How do we Choose which is best?
Solution for optimal lane choosing:
Express items = [1 .. 15]
Regular items = [10 .. 60]
People Time Distribution
vs
Let’s explore multiple-universes...
...with Monte-Carlo simulations!!!
Express = 6 Regular = 3
10,000 samples! What’s the probability Regular is faster?
5 v 3 P(Regular faster) = 0.736 v 3 P(Regular faster) = 0.92
Cost of 6 express vs 3 regular
CDF = Best Plot of All time!!!
“But your model is dumb, and I don’t like it.”
Your alternative model...
If people in the express lane is double the number in the regular line then…
P(regular is faster) = 0.99
Otherwise
P(express is faster) = 0.99
Comparing hypotheses with theLikelihood ratio
Ratio: 0.63Your model explains the data ~1.6x better!
Feeling Smart?
Your Model...
Vs.
A Coin Flip!
A coin explains the data 3.2x better than your model!
What did we learn today?
Nothing!
What did we learn today?
Nothing!
Basically all of Statistical Inference (or at least the important bits)
What did we learn today?
Nothing!
Basically all of Statistical Inference (or at least the important bits)
Everything is hard
What did we learn today?
Nothing!
Basically all of Statistical Inference (or at least the important bits)
Everything is hard
We can compare our misunderstanding of the world with the relative strength of our hypotheses
Thank you!!!
Email me at [email protected]
Follow me on Twitter @willkurt
Read about probability: https://www.countbayesie.com
Preorder my book on a totally unrelated topic: https://www.manning.com/books/learn-haskell
