ChatGPT Prompt Engineering for Developers vs HarvardX Professional Certificate in Data Science
Same Bayesian formula, same rubric — so the difference in scores reflects the difference in the courses, not the difference in how we evaluated them.
DeepLearning.AI (with OpenAI) · AI & ML Courses
ChatGPT Prompt Engineering for Developers
Harvard University (edX, PH125.x series by Rafael Irizarry) · AI & ML Courses
HarvardX Professional Certificate in Data Science
Per-criterion
Two core principles (write clear and specific instructions, give the model time to think) plus modules on iterative prompt development, summarizing, inferring, transforming, expanding, and building a chatbot. Reviewers praise the clarity and the runnable Jupyter notebooks. The honest limit is depth: it was built in April 2023 on GPT-3.5 Turbo and does not cover newer patterns like tool calling, structured outputs, or reasoning models.
Isa Fulford (OpenAI) and Andrew Ng (DeepLearning.AI) are about as authoritative as the field gets. The teacher-student dynamic — Ng asking the clarifying questions a beginner would ask while Fulford demonstrates — is repeatedly cited as a strength that mirrors how learners actually think.
Free on the DeepLearning.AI platform with every code example runnable in-browser, no API key or local setup required. Reviewers consistently call out "the best part is that it's free" as a decisive advantage over the paid prompt-engineering courses that flooded the market in 2023.
Being a one-hour self-paced short course, there is no graded assignment, cohort, or mentor support. The OpenAI and DeepLearning.AI community forums are active and useful, but learners are largely on their own. For a course this short the need is limited, but there is no structured help.
Six practical use cases implemented end-to-end give learners patterns they can apply the same day. Developers report it directly improved their ability to build LLM features. The caveat is that the API-level patterns are a foundation, not a production blueprint — several reviewers wanted more on structuring LLMs into real applications.
Nine-course breadth — R, visualisation, probability, inference, productivity tools, wrangling, linear regression, machine learning, capstone. Reviewers flag the Machine Learning course as poorly scaffolded with sharp difficulty jumps; the capstone is the strongest component.
Rafael Irizarry is a respected biostatistician (Simply Statistics, dsbook) and the content is academically solid. Pedagogically reviewers note examples pitched above true-beginner level and short videos that often defer to outside resources for depth.
One-time $792 for verified certificates across 9 courses (often discounted to ~$441), or free audit for everything except graded assignments and the certificate. Reviewers call paid accountability the main value lever, plus a modest Harvard CV signal.
Self-paced edX experience — no live TA, no office hours, peer-graded capstone with inconsistent feedback. HN and blog reviewers consistently report supplementing the lectures with DataCamp, YouTube and Stack Overflow rather than course forums.
Produces a real portfolio artefact (MovieLens recommender plus a self-chosen project) and a working R toolchain — RStudio, tidyverse, git. The honest gap is zero Python and zero SQL coverage; reviewers explicitly recommend pairing it before applying for analyst roles.
Scoring methodology applies identically to every course on the site — see the formula.