Thread Reader

Analytical Aakriti | The SQL Gal


Sep 23

7 tweets

Data Science Interview Questions Part 1 🚨 πŸ‘‰ What is look ahead bias? How to avoid it? Comment below or read along ↓

Simply put, Bias is any tendency that causes a drift between results and facts. This can be introducing while collecting, sampling or processing data. Look ahead bias occurs when a system depends on information that was not available at the time of the study.

To explain it as an illustration, it is simply putting future information to an experiment set in a previous timeframe.

Look ahead bias occurs a lot in the finance industry when designing trading strategies. Analysts design the model so it favors the real outcomes of those stocks they know now, which certainly won't be available for the model in practise.

How to prevent this? Two ways, Rolling window or Expanding window 🏠

Here's an excellent resource for Look Ahead Bias :…

Useful for Time Series Analysis, and time sensitive data.…

Look-ahead Bias & How To Prevent It's Damage

@BowTied_Raptor | Data Science Emporium is hosting a Data Science competition on problems where you might encounter this. Winner gets 1000 USD. Participate below!…

Analytical Aakriti | The SQL Gal


Data Analyst | Technical Writer | Tableau Expert | Data Analytics Educator I help you get into Data the simple, effective and no nonsense way πŸ“Š

Follow on Twitter

Missing some tweets in this thread? Or failed to load images or videos? You can try to .