Welcome to POLS 1600

Data and Measurement

Updated May 31, 2024

Overview

Goals and Expectations

Course Structure

Course Policies

A Few Fundamental Truths

Goals and Expectations

What you will learn

You will learn

how to think like a social scientist

how to use data to make descriptive, predictive, and causal claims

how to quantify uncertainty about these claims

how to present, interpret, and critique these claims

Reasons to take this class

You want to change the world

Why is this study important?

Findings provide evidence of benefits of social spending/universal basic income

Why should we believe these results

Because it’s in the Times?
Because the authors are professors at good schools?
Because of how the study was done!
- Random assignment provides a reasoned basis for inference
- Creates informative counter-factual comparisons
- Pre-registered hypotheses ensure that we’re not cherry-picking results

Why might we be skeptical of these results?

How strong are the effects?
- Is a fifth of a standard deviation a lot?
Why do we care about brain waves?
What’s the mechanism?
How confident are we that these results couldn’t have happened just by chance

Why might we be skeptical of these results?

Source: Andrew Gelman

Why might we be skeptical of these results?

Source: Andrew Gelman

Reasons to take this class

You want to change the world
- Data, design, and analysis are incredlibly powerful tools
- You want to understand their strengths and limits
You want to be a better consumer of data and knowledge
You want to be a better consumer of data and knowledge
You want to get a job / go to grad school
You have to
You’re just in it for the memes

Great expectations

I expect that you will come to class ready to engage with:

social science
data
programming
math

Requirements

I assume that you will

Do the readings

Bring your computers ¹

Work through classwork

Ask questions

Course structure

Class

Tuesday: Lecture/Demonstration
Thursday: Lab/Exploration

Class websites

Slides, labsm and additional resources available here: pols1600.paultesta.org
Assignments uploaded here: Canvas

Software and computing

Statistics done using R
- Open source (free) statistical language
Through R Studio
- An integrated development environment for R
Results written up using R Markdown
- Language for combing R code with html Markdown

R

R Studio

Quarto

Project options in YAML
Code in triple backtick chunks:
- Chunk options set with “#|” (hashpipe)

```{r}
#| label = "simulate_data"
x <- rnorm(100)
y <- 2*x + rnorm(100)
```

Write up in Markdown
Output rendered as an html file

Getting set up for the course:

Here’s a link to a guide to get you setup for the course.

Take a crack at it after class, over the weekend.

Email me with any issues (there are always issues), and drop by my office hours on Tuesday so we can trouble shoot.

Textbook

https://press.princeton.edu/books/paperback/9780691222288/quantitative-social-science

How to Read Imai

Active reading
Copy and run the code in the text. To do so, do the following:

if (!require("devtools")){
  install.packages("devtools")
  }
library("devtools")
install_github("kosukeimai/qss-package",  
               build_vignettes  =  TRUE)

How to Read Imai

Once you’ve rune the following

install.packages("devtools")
install.packages("remotes")
remotes::install_github("kosukeimai/qss-package", build_vignettes = TRUE)

Anywhere the text loads data:

afghan <- read_csv("afgahn.csv")

You can do

library("qss")
data("afghan")
summary(afghan$age)

   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  15.00   22.00   30.00   32.39   40.00   80.00

Additional Readings

Occasionally, I will provide additional readings, available on both Canvas and pols1600.paultesta.org

Assignments

You have three types of assignments in this course

Labs
Tutorials
Final Project

Labs

Each Thursday we will work in groups to complete an in-class lab
The labs are designed to reinforce and extend concepts from lecture using real world data.

Labs

Weeks 1 and 2 we’ll work collectively
Weeks 3 on, you’ll be assigned to small groups
Each week:
- Log on to the Canvas, download the lab .qmd file
- Open R Studio
- Render the qmd file to get ready to work
- Complete the lab
- Upload the rendered html file to Canvas by the end of class
One question randomly graded
- 100% if correct
- 85% if incorrect, but you tried
- 0% if you did not try/absent for the lab
Comments/Answers posted immediately after class

Problem Sets/Tutorials

Coding tutorials to reinforce concepts from lecture and textbook.
Accessed by running

learnr::run_tutorial("00-intro", package = "qsslearnr")

Complete the tutorial. Save output as “LASTNAME_TutorialNumber.pdf”
Upload output to Canvas by Friday by 11:59 pm
Grades:
- 100% any upload
- 0% no upload

Final Project

Your First Assignment:

Download and install R and R Studio
- Email me if you have troubles
- Troubleshoot by Zoom or in-person (111 Thayer Room 339)
Work through 00-software_setup before next class.

Portals of Discovery

Errors

ish happens
Seeing red is a good thing
We learn by making errors

Final Reports

Can be on any topic you like
More info to come
Due dates:
- Week 2 Groups assigned
- Week 3 Research Topics
- Week 6 Data Proposal
- Week 8 Data Explorations
- Week 11 Drafts
- Week 12 Presentations
- Week 13 Final Paper

Grading and Other Policies

Grading

5% Attendance
10% Class involvement and participation
10% Tutorials
30% Labs
20% Assignments for final paper
20% Final paper

Course policies

Academic honesty
Community standards
Incomplete/late work

Introductions

Two Fundamental Truths

Testa’s first fundamental truth

Why would I profess my utter ignorance on the first day of class?

Four possible reasons…

1. Expectation Management

2. Pedagogical Tomfoolery

3. Positionality

4. Epistemology

Testa’s second fundamental truth

Two kinds of people in this world

What is it that we say we do here

What does quantitative research do?

Descriptions

Descriptions

What does quantitative research do?

Descriptions
Explanations

Explanations

What does quantitative research do?

Descriptions
Explanations
Predictions and Uncertainty

Predictions and Uncertainty

What does quantitative research do?

Descriptions
Explanations
Predictions and Uncertainty

Two kinds of people in this world

Introductions

My research

I study American Poltical Behavior with focus on poltics of race and criminal justice
How do we break cycles of inequality when those most affected by injustice are the least likely to participate and those unaffected are the least likely to care?
How can we use methodological tools to better answer these questions?

But enough about me

Class survey

Please click here to take a brief survey that will help me structure the class going forward.

Next Week:

Complete the class survey
Download and Install R and R studio
Read Chapters 1 (Friday) and start Chapter 3 in QSS
Tuesday: Lecture: Describing Data in R
Thursday: Lab: Exploring COVID-19 data in the US
Friday: Submit Tutorials: “00-intro” & “01-measurement”
- Only time you’ll have two tutorials due (Ok to submit late)