1. What data is and why people use it
Data begins when something about the world is recorded so it can be examined later.
A customer places a carton of milk on a checkout counter. The scanner reads a product code. The checkout records a time, a branch, a quantity and a price. The sale happened in the world; the stored facts are data about the sale.
Data is recorded evidence. It can describe an event, object, place, process or measurement. A number can be data, but so can a word, date, image, sound or yes/no answer. What makes it useful is not its shape. It is the connection between the recorded value and what that value is meant to describe.
The event is not the record
A checkout record is not the sale itself. It is a deliberately limited description of the sale. It may record the product and price but not whether the customer was in a hurry. Every record includes some facts and leaves others out.
| World event | Recorded value | Meaning |
|---|---|---|
| a product crosses the scanner | P-1042 | the product identifier |
| the sale completes | 18:42 | the recorded checkout time |
| two cartons are sold | 2 | the recorded quantity |
| payment succeeds | card | the payment category |
A checkout receipt says product P-1042, quantity 2, time 18:42. Which part is the event and which parts are data?
- Identify what happened: two units of a product were purchased at a checkout.
- Identify what was retained: the product identifier, quantity and recorded time.
- Keep the two ideas separate. The values describe the event; they are not the physical event.
Answer. The purchase is the event. P-1042, 2 and 18:42 are recorded data about it.
| Event | Recorded data |
|---|---|
| two cartons are purchased | P-1042 · quantity 2 · 18:42 |
A record can be incomplete or wrong even when the event truly occurred.
answer
The event is the sensor taking a temperature measurement. The recorded data is 6°C together with the time 07:00; the sensor and location are also needed as context.Data takes many forms
A common beginner mistake is to equate data with numbers. Qubix Superstore uses quantities and prices, but it also uses branch names, product categories, timestamps, delivery photographs and written incident notes. Each form can preserve evidence.
| Form | Example | What it describes |
|---|---|---|
| number | 14 | units sold |
| text | North | region name |
| date | 2026-08-21 | business date |
| yes/no | yes | promotion active |
| image | shelf photo | visible shelf condition |
Classify these as possible data: a price, a branch name, a delivery photograph and a spoken customer comment.
- Do not ask whether the item is a number.
- Ask whether it records something that can be examined later.
- All four retain evidence: an amount, a category, a visual condition and spoken words.
Answer. All four can be data.
| Record | Form |
|---|---|
| £3.20 | number |
| Central | text |
| shelf.jpg | image |
| audio note | sound |
Later topics will distinguish structured and unstructured data. This book needs only the broader idea.
answer
Yes. Each records evidence in a defined form.A value without context can mislead
Suppose someone sends you the number 14. It could mean fourteen items, fourteen pounds, branch fourteen, fourteen minutes, or a temperature of fourteen degrees. The digits are present, but their meaning is missing.
- A label says what was recorded.
- A unit says how a quantity was measured.
- A time says when it was true.
- A source says where it came from.
- A grain says what one complete record describes.
A message says only “14”. What must you ask before using it in a branch report?
- Ask what the value describes.
- Ask for its unit if it is a measurement.
- Ask which branch or product it belongs to.
- Ask when it was observed and which system produced it.
Answer. Request the label, unit, subject, time and source before treating 14 as evidence.
Guessing the missing meaning manufactures data that was never supplied.
answer
What does 6 describe, and in what unit or category is it recorded? Time, source and subject usually follow.Why people record data
People record data because memory is limited and decisions need evidence. A single branch manager can remember that a delivery was late. A company with 48 branches needs consistent records to find repeated delays, compare suppliers and decide where to intervene.
- Remember: preserve evidence after an event has passed.
- Describe: state what is happening now.
- Compare: examine differences across time, products or branches.
- Monitor: notice when a process moves outside an expected condition.
- Decide: choose an action using the available evidence.
- Learn: test whether an action produced the intended result.
Branch B014 records a stockout for milk at 18:42. How can that one record support a decision?
- The record preserves the event after the shelf has been refilled.
- Combined with other records, it can reveal how often the product is unavailable.
- The branch can compare stockouts with deliveries and sales.
- A manager can change an order only after checking that the evidence is accurate and relevant.
Answer. The record becomes useful when it is combined with context and related evidence to support a replenishment decision.
Data supports a decision; it does not make the decision automatically.
answer
Record the supplier, order, promised time, actual arrival time, branch or hub, and relevant circumstances; then compare with other deliveries rather than judging from an isolated memory.Data can be wrong, incomplete or harmful
Recorded does not mean true. A scanner can fail, a person can mistype a code, a clock can be wrong and a field can be left blank. Data can also expose people or be collected without a fair purpose. Good data work therefore keeps evidence of uncertainty, protects privacy and documents corrections rather than quietly inventing values.
Reference and provenance record
Terminology was cross-checked against David M. Lane and collaborators, Online Statistics Education: An Interactive Multimedia Course of Study, Introduction and “Variables,” OnlineStatBook/Rice University. The source site states that the work is in the public domain and requests citation. Stable records: https://onlinestatbook.com/2/index.html and https://onlinestatbook.com/2/introduction/variables.html (accessed 21 August 2026).
The Qubix Superstore company, event trail, identifiers, records, examples and questions are original synthetic teaching material. They describe no real customer, employee, branch or retailer.
- Corethe standard set
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A customer buys bread. The checkout stores product B-12 and quantity 1. What is the event?Recognise
show solution
The event is the customer purchasing one bread product. The stored identifier and quantity are data about it.
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In the same example, name two recorded data values.Recognise
show solution
B-12 and 1.
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Is a branch name data even though it is text?Recognise
show solution
Yes. It records which branch is being described.
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Is a shelf photograph capable of being data?Recognise
show solution
Yes. It can preserve visible evidence about the shelf at a particular time and place.
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Explain why the number 27 is not useful by itself.Explain
show solution
Its label, unit, subject, time and source are unknown, so its meaning is unsettled.
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What is the difference between a sale and a sale record?Explain
show solution
The sale is the real-world event. The sale record is a limited stored description of that event.
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A record says “North, 08:00, 6°C”. What does the unit contribute?Explain
show solution
The °C tells us that 6 is a temperature measured on the Celsius scale rather than a count, identifier or another quantity.
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Give one reason people record data rather than rely on memory.Explain
show solution
Records preserve evidence after events pass and allow consistent comparison across many events, places or times.
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Which is a safer response to a blank stock count: enter zero or mark it missing and investigate?Decide
show solution
Mark it missing and investigate. Zero asserts that no stock existed; a blank does not establish that.
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A checkout clock is ten minutes fast. Can its timestamps still be recorded data?Decide
show solution
Yes, but they are inaccurate records of the true time. Recorded does not guarantee correct.
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Name two forms of data that are not ordinary numbers.Recall
show solution
Any two of text, dates, yes/no categories, images, sound or video.
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What does a source tell you?Recall
show solution
It tells you where a value or record came from, such as a checkout, sensor, survey or supplier system.
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Why should a correction retain evidence of what changed?Explain
show solution
So another person can trace the original record, understand the correction and audit the result instead of trusting an unexplained replacement.
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A manager sees one late delivery and dismisses the supplier. What is weak about the evidence?Decide
show solution
One event may not represent the supplier’s usual performance, and the manager has not checked context or compared other deliveries.
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List the four steps in the book’s central data flow.Recall
show solution
Event, record, organised table or collection, and use in a decision.
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Does data make a decision automatically?Explain
show solution
No. Data supplies evidence. People or defined systems still interpret it, consider limitations and choose an action.
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A field contains “card”. What kind of thing might it record?Apply
show solution
It might record a payment category. The field label and documentation are needed to confirm that interpretation.
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Why can two records of the same event disagree?Explain
show solution
They may use different clocks, instruments, definitions or entry processes, or one may contain an error.
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What privacy question should be asked before collecting a new field?Decide
show solution
Is the field genuinely needed for a stated fair purpose, and can that purpose be achieved with less personal data?
- Stretchthese need a decision, not just a method
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In one sentence, define data for this course.Reconstruct
show solution
Data is recorded evidence about an event, object, place, process or measurement that can be examined later with its context.
Answers, shown
Every practice item is answered here, with the reasoning that produces it and, wherever a picture says it better than a sentence, the picture. 0 of 20 are drawn so far. A book that answers only the odd numbers teaches its reader to guess.
1. What data is and why people use it
A customer buys bread. The checkout stores product B-12 and quantity 1. What is the event?
The event is the customer purchasing one bread product. The stored identifier and quantity are data about it.
In the same example, name two recorded data values.
B-12 and 1.
Is a branch name data even though it is text?
Yes. It records which branch is being described.
Is a shelf photograph capable of being data?
Yes. It can preserve visible evidence about the shelf at a particular time and place.
Explain why the number 27 is not useful by itself.
Its label, unit, subject, time and source are unknown, so its meaning is unsettled.
What is the difference between a sale and a sale record?
The sale is the real-world event. The sale record is a limited stored description of that event.
A record says “North, 08:00, 6°C”. What does the unit contribute?
The °C tells us that 6 is a temperature measured on the Celsius scale rather than a count, identifier or another quantity.
Give one reason people record data rather than rely on memory.
Records preserve evidence after events pass and allow consistent comparison across many events, places or times.
Which is a safer response to a blank stock count: enter zero or mark it missing and investigate?
Mark it missing and investigate. Zero asserts that no stock existed; a blank does not establish that.
A checkout clock is ten minutes fast. Can its timestamps still be recorded data?
Yes, but they are inaccurate records of the true time. Recorded does not guarantee correct.
Name two forms of data that are not ordinary numbers.
Any two of text, dates, yes/no categories, images, sound or video.
What does a source tell you?
It tells you where a value or record came from, such as a checkout, sensor, survey or supplier system.
Why should a correction retain evidence of what changed?
So another person can trace the original record, understand the correction and audit the result instead of trusting an unexplained replacement.
A manager sees one late delivery and dismisses the supplier. What is weak about the evidence?
One event may not represent the supplier’s usual performance, and the manager has not checked context or compared other deliveries.
List the four steps in the book’s central data flow.
Event, record, organised table or collection, and use in a decision.
Does data make a decision automatically?
No. Data supplies evidence. People or defined systems still interpret it, consider limitations and choose an action.
A field contains “card”. What kind of thing might it record?
It might record a payment category. The field label and documentation are needed to confirm that interpretation.
Why can two records of the same event disagree?
They may use different clocks, instruments, definitions or entry processes, or one may contain an error.
What privacy question should be asked before collecting a new field?
Is the field genuinely needed for a stated fair purpose, and can that purpose be achieved with less personal data?
In one sentence, define data for this course.
Data is recorded evidence about an event, object, place, process or measurement that can be examined later with its context.
What this book still owes its reader
A chapter passes when it carries at least 4 worked examples, each followed by a parallel one the reader does; at least 4 figures; an illustrated or operable answer on every worked example; at least 20 practice items with an answer for every one; a named misconception; and a link back to earlier work. This table is counted from the source at build time, so it cannot flatter the book.
| Chapter | Requirements met | Labs | Figures | Practice | |
|---|---|---|---|---|---|
| 1What data is and why people use it | 8 of 8 | — | 18 | 20 | passes |
1 of 1 chapters meet the gate. 20 practice items, every one with a solution you can open; 4 worked examples carrying 4 parallel exercises and 4 illustrated answers; 0 interactive labs; and 18 figures, every one computed at build time from the formula printed beside it.