A familiar place can become a new question¶
Think about a journey you make often. You may know where to change trains, which stop is busiest, or which route feels easiest after a long day. That knowledge already contains geography: locations, connections, differences between places, and experiences that vary from person to person.
Now imagine looking at the same journey through data. You see stations with different boarding counts, flows that are stronger in one direction, or neighbourhoods with very different housing prices. A familiar place begins to raise questions. What exactly was counted? Is a busy place unusual, or simply surrounded by more opportunities for activity? Does a pattern change when we look at another hour, neighbourhood or spatial scale?
This book begins with that movement from noticing to asking. Its central question is: Why do some places seem different from others—and how can we tell what the patterns we notice mean? You can begin without knowing a statistical test or a GIS command. Bring an observation, a willingness to inspect it, and a readiness to revise an initial explanation.
Seeing a pattern is the beginning¶
Suppose a display shows more expensive resale transactions in one part of Singapore. That is worth noticing. It immediately creates several possible questions: are homes there more expensive, are more homes being sold there, or does the display combine different types and sizes of flat? Each question calls for a different comparison.
The same habit applies beyond housing. A group of satellite fire detections might reflect environmental conditions, repeated observations or the detection process. Similar incomes in neighbouring Malaysian areas might reflect a regional pattern or the way observations have been grouped. An MRT flow may connect two stations strongly even when a simple proximity sketch tells us little about the journeys between them.
These examples lead us into different parts of the book. We will learn methods for describing distributions, examining point patterns, comparing groups and exploring neighbouring areas. Before reaching for those methods, however, we need a question and an understanding of what our observations represent.
What the book offers¶
The book connects three practices. Visual exploration makes observations available for inspection. Statistical reasoning helps us choose comparisons and explain uncertainty. Geographical reasoning asks why locations, boundaries, connections and spatial scale matter to those comparisons. Each practice strengthens the others: a map can suggest a question, a calculation can challenge an impression, and knowledge of a place can reveal a missing explanation.
The examples are mainly from Singapore and the surrounding region. MRT records introduce data structure; bus ridership supports statistical comparisons; Indonesian fire detections introduce point-pattern questions; HDB resale records support density and clustering examples; Malaysian income data introduces areal relationships. Chapter 7 combines housing, bus activity and selected amenities to examine how evidence becomes a coherent visual story.
| Chapter | A question to carry forward |
|---|---|
| 2. Data and spatial data | What does an observation represent, and how do we prepare it? |
| 3. Statistical patterns | What comparison answers the question, and what uncertainty can we assess? |
| 4. Point patterns | How are events arranged, relative to a stated reference expectation? |
| 5. Local point patterns | Where are concentrations, and how do our measures and parameters shape them? |
| 6. Spatial autocorrelation | How do values relate across a chosen neighbourhood structure? |
| 7. Geovisualisation and storytelling | How can we communicate an evidence-based interpretation clearly? |
How to read and explore¶
Start with the questions and figures. Try to describe what you see before reading the interpretation. When a self-check appears, pause long enough to form an answer; the feedback explains the reasoning rather than merely giving a label. Equations and notebooks later in the book make the operations precise, while the reading explains why those operations are useful.
If you already know a method, use the examples to examine its assumptions and geographical meaning. If you are new to the topic, first follow the observation, question and comparison; return to the calculation once their connection is clear. Worked examples and notebook collections provide additional routes through the material.
The next four pages introduce visual, statistical and geographical ways of thinking. Their purpose is to help you enter the subject and recognise what you want to investigate. Detailed calculations, data preparation and design guidance appear where they become useful in the later chapters.
Begin here: choose one observation
Think of a place or journey you know. Complete these sentences: “I notice ...”, “I wonder whether ...”, and “To investigate, I would need ...”. Several questions can be reasonable. Keep your answer and revisit it after Chapter 2: has your definition of an observation changed?