The Statistics Before the Statistics

Realizing It Was Never Just About the Math

Alex Zajichek, Data Scientist

Department of Quantitative Health Sciences
Cleveland Clinic

September 30, 2026

Who Am I?

AI-me*

*I have justification for this

What are these slides about?

My evolution in statistical problem solving and how Dr. Kattan helped shape it.

Hired out of school by Mike. Special thanks to Jim Bena.
When I started I was at my peak in terms of technical knowledge, statistical theory, etc. I could still do advanced calculus and make derivations
Little did I know I knew nothing about statistics in the real world.
Mindset was “if this then do this method”. It was objective/systematic. Run procedure, check diagnostics, calculate pvalue, GET conclusion
I remember explicitly mikes email on
roughly my 3rd day. “Here’s something to get your feet wet with.” It was some R code to compute a c-index (using frank harrells rms package). He wanted me to run it for some new predictions he had and send him the results. “Sure here you go!”. It was something like this: (show some R code/output).
- “That looks backwards”. I was confused. Then he told me the minimum value is .5, you need to flip the labels.
- I didn’t even know what this meant. He clarified it’s like an AUC. “Oh I’ve done that”. But I never had an intuitive understanding of what it was telling us. Just knew higher was “better”.
- So then the next part: is this good? (looks at recommended thresholds). Maybe? But what if it’s better than the current standard of care/decision making process? “Hmm I never thought of it like that” I guess there is not an objectively right answer. It depends on the context.
- This story is the first time I really began thinking that statistics is more than objective math. It’s subjective problem solving.

Fresh Graduate
Started at CCF

The work becomes visible once there is something others can try, question, and react to.

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