Hello,  my name is...

 

Dhrumil Mehta (he/him)


dhrumil.mehta@columbia.edu

 @datadhrumil

@dmil

Highlights:

Currently

  • Associate Prof. @ Columbia Graduate School of Journalism

  • Visiting Associate Prof. @ Harvard Kennedy School

 

Previously

  • Database Journalist, Politics @ FiveThirtyEight

  • Software Development Engineer @ Amazon
  • Northwestern:
    • BA in Philosophy + Minor in Cognitive Science
    • MS in Computer Science

Database Journalist, Politics

Polls

Is polling becoming less accurate?

Is horserace polling becoming less accurate in the US?

Is horserace polling becoming less accurate in the US?

 

https://www.monmouth.edu/polling-institute/reports/monmouthpoll_ga_102820/

Title Text

Polling error tends to be correlated in a given election cycle

Is horserace polling becoming less accurate in the US?

Communicating Uncertainty

Interpreting Summary Statistics

What is included?

 

What is excluded?

 

Methodological choices / assumptions

Inferential Statistics

Parameters are numbers that summarize data for an entire population. Statistics are numbers that summarize data from a sample, i.e. some subset of the entire population.

 

- source: David Gurney 

Remember "margin of error" is only the margin of sampling error. There are other sources of error as well.

Communicating Uncertainty

Communicating Uncertainty

Polls are not a crystal ball 🔮

 

  1. They are a "snapshot in time"
  2. They are a statistical sample
  3. Election polls are built upon assumptions of who will turn out to vote -- "likely voters".

 

 

 

They're one piece of information that can help you better understand state of a race.

 

Don't ignore them. But don't worship them.

Some journalists who talk about polls in US elections on Twitter

Ariel Edwards Levy - CNN (formerly HuffPost)
@aedwardslevy

G Elliott Morris - The Economist
@gelliottmorris

 

Lenny Bronner - Washington Post
@lennybronner

Nate Cohn - New York Times
@Nate_Cohn

Nate Silver - FiveThirtyEight
@NateSilver538

 

Final thoughts

  • When it comes to issue polling -- always look for as many polls as you can find on a particular topic. Start with a spreadsheet!
     
  • When it comes to election polling -- follow the conversation that pollsters and aggregators are having. There are also important signals coming from academia and research centers, especially retroactively.
     
  • To understand the quality of a particular pollster, pay attention to their historical track record of accuracy. Try to avoid building a story around a single poll.
     
  • Beware of fake polls. Like all forms of misinformation, they're on a sliding scale of "fakeness". 


dhrumil.mehta@columbia.edu

 @datadhrumil

@dmil


http://fivethirtyeight.com/contributors/dhrumil-mehta/​

ma-ptx-2022

By Dhrumil Mehta

ma-ptx-2022

Saying hello to students

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