Dhrumil Mehta
Database Journalist, Politics @ FiveThirtyEight
(1) Please make and display your name cards!
(2) Make sure you're on Slack:
https://ledeprogram.slack.com/
If you have any questions, just raise your hand 🖐!
Welcome! Let's get rolling!
- Homework Review: Assignment 1
- Guest Speaker: Nathaniel Rakich
- Intro to Stats for Journalists
- Activity 1
- Lecture
- Activity 2
- Homework Preview: Assignment 2
- Project Brainstorming: "speed dating"
Homework Review
Headlines / Key Takeaways
Anonymous
Polling error: How one survey changed the Newsom recall campaign - CalMatters
SurveyUSA CEO Jay Leve admits that their earlier poll could have acted as an alarm clock. “It was not our intention to cause Democrats to suddenly sit bolt upright in their chairs,” he told CalMatters. And yet, “that, I think, happened.”
Mea Culpa - SurveyUSA
Always spend some time with the primary source materials in addition to reporting around that source material.
In this case:
- Poll PDFs (Toplines / Crosstabs)
- Press Releases
- Conversations with experts
- Academic discussions & articles about those polls
- News about the polls themselves (like the CalMatters article)
✅ Looking for "apples-to-apples" comparisons
✅ Context on how often this has happened before
✅ Explaining events around the key turning points, without making strong causal claims
⚠️ Reporting levels of precision in data
⚠️ Claims about the data's predictive value
⚠️ Causal Claims
⚠️ Keeping in mind the temporal element
Ben Orlin — Math with bad drawings
Ben Orlin — Math with bad drawings
Text
Examples
Ben Orlin — Math with bad drawings
Ben Orlin — Math with bad drawings
Examples
Ben Orlin — Math with bad drawings
Ben Orlin — Math with bad drawings
Ben Orlin — Math with bad drawings
Ben Orlin — Math with bad drawings
https://www.investopedia.com/terms/n/negative-correlation.asp
Pearson's Correlation Coefficient
Correlation doesn't imply causation, but it does waggle its eyebrows suggestively and gesture furtively while mouthing 'look over there'.
Ben Orlin — Math with bad drawings
Ben Orlin — Math with bad drawings
Examples
Ben Orlin — Math with bad drawings
Ben Orlin — Math with bad drawings
https://docs.google.com/spreadsheets/d/1fywjh2itH6p8Vpld8LAprdwXzsDByEhXiN5HqTQtpOM/edit#gid=0
What can you tell about these 4 mystery datasets with summary statistics?
Calculate:
- Mean
- Median
- Mode
- Correlation
- Variance
https://fivethirtyeight.com/features/al-gores-new-movie-exposes-the-big-flaw-in-online-movie-ratings/
Exploratory Data Visualization
Pearson correlation is ????
Pearson correlation is 0.9909
Who is the most Democratic-leaning pollster?
Are state polls less accurate than national polls?
Which states has the most inaccurate presidential polling?
How predictive are recall elections polls?
Who is the most Democratic-leaning pollster?
Are state polls less accurate than national polls?
Which states has the most inaccurate presidential polling?
How predictive are recall elections polls?
Who is the most Democratic-leaning pollster?
Are state polls less accurate than national polls?
Which states has the most inaccurate presidential polling?
How predictive are recall elections polls?
Who is the most Democratic-leaning pollster?
Are state polls less accurate than national polls?
Which states has the most inaccurate presidential polling?
How predictive are recall elections polls?
I have a dataset I'm interested in
I have a journalistic question that I'm interested in trying to answer
Does your pitch start with a:
What questions will I ask?
Where will I get the data?
project group "speed dating"
https://forms.gle/bzjmNvmXaqAmygjU7
Slack
https://ledeprogram.slack.com/
#data-ms-2022
#data-ms-2022-discussion
#data-ms-2022-coding
OR
directly message Dhrumil/Aseem
Office Hours
Dhrumil
Weekdays 2-4pm
Aseem
Night before your assignment is due: 6-9pm
During the week...
By Dhrumil Mehta