Fundamentals of Data Science

John P. McCrae - University of Galway

Course at ESSLLI 2025

Course Overview

Lectures

• Mon: Fundamentals of Data Science
• Tue: Linguistic Data Science
• Wed: Syntax
• Thu: Semantics (incl. Large Language Models)
• Fri: Multilinguality

Course materials

• Webpage - https://john.mccr.ae/lds-esslli25
• Access to all code and slides through this URL

Hands-on sections

• We will use Python
• Very simple examples, no previous knowledge required
• You will need your laptop to follow along!

About me

• Assistant Professor at University of Galway, Ireland
• Researcher in NLP, Linked Data, Digital Humanities
• More at https://john.mccr.ae

About you

What is Data Science?

What is Linguistic Data Science?

Data Ingestion

• Structured Data
  • such as CSV, databases, XML
• Unstructured Data
  • such as text, images, audio

Data Storage

• Cleaning
• Deduplication
• ETL
• Databases

Data Analysis

• Data Exploration
• Predictive Analytics
• Machine Learning

Communication

• Visualisation
• Reporting
• Dashboards

Examples of Data Science

• Customer Analytics
• Supply Chain Optimisation
• Improving Patient Care

Methods for Data Science

Data Storage

SQL

SELECT * FROM table WHERE condition

Data is stored in a tables; can be difficult to represent complex data

NoSQL

{
  "name": "John McCrae",
  "affiliation": "University of Galway",
  "email": "john@mccr.ae"
}

Flexible data structures; can be difficult to query

Graph Databases

(John McCrae)-[:affiliation]->(University of Galway)
(John McCrae)-[:email]->(john@mccr.ae)

More flexibility but can be very slow to query

Scaling Tools

Apache Hadoop

Based on MapReduce

Map-Reduce

Splitting

...

Map-Reduce

Mapping (word length)

...

Map-Reduce

Reducing (average)

Apache Spark

• Based on Resilient Distributed Datasets (RDDs)
• Streaming and batch processing

Analytic Tools

Jupyter/Colab

• Go to https://colab.research.google.com
• Create a new notebook

Pandas

• Library for data science in Python
• Try the following

import pandas as pd
data = pd.read_csv("https://raw.github" +
"usercontent.com/cs109/2014_data/" +
"master/countries.csv")
data.describe() 

Other languages

• R - Very popular in statistics
• Julia - New fast language for data science
• Scala - Java-based functional programming
• Rust - Fast and safe systems programming

Visualisation Tools

D3.js

Matplotlib

import matplotlib.pyplot as plt
plt.hist(data["Region"])

Seaborn

Introduction to Python and Colab

Basic Python

print("Hello, World!")

Variables

x = 5
y = 3
print(x + y)

Variables can be used to store data and can be changed at any time

Control Structures

if x > y:
  print("x is greater than y")
else:
  print("y is greater than x")

Python uses indentation to define blocks of code

Functions

def add(x, y):
  return x + y
print(add(5, 3))

Functions can be used to define reusable code

Batteries included

import math
print(math.sqrt(9))

Python has many libraries for common tasks

Natural Language Processing

NLP as a Black Box

Sentiment Analysis

Annotation

Parsing

Machine Translation

Natural Language Generation

Information Extraction

Machine Learning

Supervised Learning

Unsupervised Learning

Reinforcement Learning

Deep Learning (pretrained models)

Summary

Summary

• Linguistic Data Science is application of data science to linguistics
• Answers linguistic questions using:
• Big Data
• Natural Language Processing
• Machine Learning