Another One Writes the Code

Generative AI can now write code across the data science lifecycle and produce plausible interpretations, challenging core assumptions about what beginners should learn and how they should be assessed. This talk examines the redesign of an introductory data science course at Duke University in response to these shifts. Some changes were made because of AI, including new in-class assessments; others were made thanks to AI, such as integrating just-in-time feedback in the IDE. I will discuss what changed, what failed, what improved, and how student feedback—ranging from enthusiasm to skepticism—is shaping an evolving approach to teaching data science in the age of generative AI.

Transcript

1. ANOTHER ONE WRITES THE CODE mine çetinkaya-rundel duke university + posit pbc
4. fetch tidy + transform summarize visualize
6. Should we still ask students to learn to do these things themselves? > > Yes.
7. THREE PROMPTS, THREE QUIET PROBLEMS. THREE PEDAGOGICAL APPROACHES.
8. DISCLAIMER : Real datasets and analyses were indeed harmed in making these examples.
9. PROMPT 1. ” > “join these data frames
10. Student names and scores are in two different files: roster.csv and scores.csv. Create a single data frame with student IDs and names from the roster file and the scores for these students from the scores file. roster read_csv("data/roster.csv") scores read_csv("data/scores.csv") - # A tibble: 203 × 2 id score <dbl> <dbl> 1 1 83 2 2 75 3 3 50 4 4 70 5 5 74 6 6 88 7 7 50 8 8 81 9 9 79 10 10 75 # ℹ 193 more rows - # A tibble: 102 × 2 id name <dbl> <chr> 1 1 Micah Das 2 2 Zara Wright 3 3 Jayden Reed 4 4 Samira Mitchell 5 5 Isla Thomas 6 6 Celine Smith 7 7 Asha Anderson 8 8 Isaac Ndlovu 9 9 Lucas Sato 10 10 Max Nelson # ℹ 92 more rows < scores < roster
11. 🤖 With AI Create a single data frame with student IDs and names from the roster file and the scores for these students from the scores file. ↑ roster left_join(scores, join_by(id), relationship = "many-to-many") : > | ) # A tibble: 105 × 3 id name score <dbl> <chr> <dbl> 1 1 Micah Das 83 2 2 Zara Wright 75 3 3 Jayden Reed 50 4 4 Samira Mitchell 70 5 5 Isla Thomas 74 6 6 Celine Smith 88 7 7 Asha Anderson 50 8 8 Isaac Ndlovu 81 9 9 Lucas Sato 79 10 10 Max Nelson 75 # ℹ 95 more rows Sonnet 4.6 (via Posit AI
12. 👩💻 Without AI roster left_join(scores, join_by(id)) : > | Warning message: In left_join(roster, scores, join_by(id)) : Detected an unexpected many-to-many relationship between `x` and `y`. ℹ Row 21 of `x` matches multiple rows in `y`. ℹ Row 54 of `y` matches multiple rows in `x`. ℹ If a many-to-many relationship is expected, set `relationship = "many-to-many"` to silence this warning. # A tibble: 105 × 3 id name score <dbl> <chr> <dbl> 1 1 Micah Das 83 2 2 Zara Wright 75 3 3 Jayden Reed 50 4 4 Samira Mitchell 70 5 5 Isla Thomas 74 6 6 Celine Smith 88 7 7 Asha Anderson 50 8 8 Isaac Ndlovu 81 9 9 Lucas Sato 79 10 10 Max Nelson 75 # ℹ 95 more rows
13. 👩💻 Without AI roster slice(21) scores # A tibble: 1 × 2 id name <dbl> <chr> 1 21 Owen Rossi scores filter(id # A tibble: 1 × 2 id score <dbl> <dbl> 1 51 64 21) roster filter(id = # A tibble: 3 × 2 id name <dbl> <chr> 1 51 Grace Baker 2 51 Grace Baker 3 51 Elliott Rundel = = = : > > > > | | | | # A tibble: 4 × 2 id score <dbl> <dbl> 1 21 83 2 21 85 3 21 80 4 21 84 slice(54) 51)
14. 🤖 With AI Can you explain what it means to allow for “many-to-many relationships? ↑ Many-to-many means the join key is not unique in either table, so each matching key produces a Cartesian product of matching rows (rows multiply). dplyr warns by default because this often indicates a mistake; setting relationship = "many-tomany" tells dplyr you expect that behavior and to proceed. Sonnet 4.6 ” : ) (via Posit AI
15. C U R I O S I T Y
16. 🤖 With AI Create a single data frame with student IDs and names from the roster file and the scores for these students from the scores file. ↑ […] Two data quirks worth knowing about, since they're why the result has 105 rows instead of 100 (dplyr will also print a "many-to-many relationship" warning about them): 1. Student 21 has four different scores in scores.csv 83, 85, 80, 84 , so that student appears four times in the joined result. If these are repeated attempts and you want one row per student, you could average them first. ) > ( ~ : 2. The roster has duplicate entries for id 51 — "Grace Baker" listed twice, plus a conflicting "Elliott Rundel" under the same id. roster % % distinct() removes the exact duplicate, but the Baker/Rundel conflict is something you'd need to resolve based on which record is correct. If the duplicates are intentional (e.g., multiple test attempts), the plain left_join above is all you need — you can silence the warning by adding relationship = "manyto-many" to the join. Fable 5
17. 🤖 With AI Create a single data frame with student IDs and names from the roster file and the scores for these students from the scores file. ↑ Opus 4.8 : ) (via Posit AI
18. PROMPT 2. ” > “plot a regression line
19. 🤖 With AI Create a scatterplot of miles per gallon (mpg) vs. displacement (disp) in mtcars, and overlay the regression line for predicting mpg from disp. ↑ ggplot(mtcars, aes(x = disp, y = mpg)) + geom_point() + geom_smooth(method = "lm", se = FALSE) Opus 4.8 : ) (via Posit AI
21. 🤖 With AI Create a scatterplot of miles per gallon (mpg) vs. displacement (disp) in mtcars, and overlay the regression line for predicting mpg from disp. ↑ ggplot(mtcars, aes(x = disp, y = mpg)) + geom_point() + geom_smooth(method = "lm", se = FALSE) Opus 4.8 : ) (via Posit AI
22. 🤖 With AI Now limit to cars with displacement below 200. ↑ mtcars filter(disp < 200) ggplot(aes(x = disp, y = mpg)) + geom_point() + geom_smooth(method = "lm", se = FALSE) Opus 4.8 > | : > | ) (via Posit AI
24. C I R U M O A S T T I S E Y R Y
25. PROMPT 3. ” > “fit a model
26. The poisson.csv file contains data on count observations, along with two features: one numerical and the other categorical. Fit a Poisson regression model to these data with R. Report the estimates for the regression coefficients you obtain and interpret them in the context of the data. dat read.csv("poisson.csv") Term Intercept fit glm( y ~ x1 + factor(x2), family = poisson(link = "log"), x1 data = dat ) summary(fit) exp(coef(fit)) x2 = b Estimate Exp(estimate) 1.5579 0.1939 0.0441 ↑ Interpretation For observations with x2 = a and x1 4.7490 = 0, the expected count is about 4.75. A one-unit increase in x1 multiplies the expected count by 0.824, or 0.8238 decreases it by about 17.6%, holding x2 fixed. Observations with x2 = b have an expected count about 4.3% lower 0.9569 than those with x2 = a, holding x1 fixed. GPT 5.5 : - - < < Medium - - - 🤖 With AI
27. 🤖 With AI Check if this model is a good fit. ↑ […] The conclusion is that the simple Poisson regression captures some mean structure, but it does not adequately model the variability in the count response. A better next step would be to fit either a quasi-Poisson model or a negative binomial regression. In this dataset, a negative binomial model gives much better evidence of handling the extra-Poisson variation. GPT 5.5 : - Medium
28. 👩💻 Without AI : The poisson.csv file contains data on count observations, along with two features: one numerical and the other categorical. Fit a Poisson regression model to these data with R. Report the estimates for the regression coefficients you obtain and interpret them in the context of the data.
29. C M S I R U K O A E S P T T T I S E I Y R C Y I S M
30. THREE PROMPTS, THREE QUIET PROBLEMS. THREE PEDAGOGICAL APPROACHES.
31. APPROACH 1. ” Level the playing field with explicit “how to best AI instruction
32. ✅ Small periodic doses, not a single lecture. ✅ Explicit examples for proper, sufficient citation, not expecting students get it right. ✅ Expect to update each semester, if not more often. ✅ Also teach the what, the how, and the ethical considerations. ” Level the playing field with explicit “how to best AI instruction
33. APPROACH 2. Emphasize workflow best practices, especially version control
34. This analysis neglected that some values in the raw data are in parentheticals, meaning they're negative values. Fix this issue in the Quarto file. ↑ Emphasize workflow best practices, especially version control
35. APPROACH 3. Shift AI use from taking shortcuts, towards supporting learning ) (+ experiment with building with AI
36. PRIOR ART
37. TODAY
38. AGENTS.md - for HOMEWORK github.com/sta199/agents-md
39. AGENTS.md - iterate… github.com/sta199/agents-md
40. AGENTS.md - for LAB github.com/sta199/agents-md
41. FROM “THE ART OF STATISTICS “There is no substitute for simply looking at data properly.” ” David Spiegelhalter Professor, University of Cambridge
42. du.ke/write-code T H A N K Y O U mine çetinkaya-rundel duke university + posit pbc