Leeds, leeds and LEEDS
A report shows three towns: Leeds, leeds and LEEDS. The computer sees three different places.
Before you trust a result, make the data look the same. Then check the answer a second way.
Key words
| Word | What it means | Example |
|---|---|---|
| Standardisation | making values follow one agreed format | |
| Validation | checking a value is sensible and in the right format | |
| Verification | checking a result is correct, often a second way | |
| Cross-checking | comparing a result with another source or method | |
| Format | the way a value is written | 2026-04-03 |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can standardise a format and cross-check a result.
Starter
Have a go
Starter
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Standardise before you compare
Standardisation means every value follows one format. Dates become year-month-day. Towns have one spelling and one case.
Equal values must look equal. If not, a join or a total treats them as different.
Try it: tidy the towns and dates
select upper(left(trim(branch), 1)) || lower(substr(trim(branch), 2)) as branch,
strptime(sale_date, '%d/%m/%Y')::date as sale_date,
pence
from branch_sales;
-- Try it: use upper(trim(branch)) to make capitals instead.Check
Have a go
Check
3 questionsHave a go: your answers are marked here and then forgotten. Sign in if you would like your score kept, and to pick up where you left off.Sign in to keep your score
Your answers are marked here and are not kept. A college account keeps every student’s marks.