The Saturday spike
A bakery owner stares at a column of numbers. Sales rise through the week and jump on Saturday, then crash on Sunday.
Is that a pattern or luck? A picture would show it at once. Finding trends and patterns means choosing how to look, and then judging what you see.
Key words
| Word | What it means | Example |
|---|---|---|
| Trend | A general direction over time: up, down or flat. | Sales rising through the week |
| Pattern | Something that repeats. | A Saturday peak every week |
| Dashboard | One screen that shows the main numbers and charts. | Sales, stock and staff |
| Graph | A picture of numbers using bars, lines or points. | A bar graph of daily sales |
| Level of detail | How much information you show. | By day or by week |
| Accuracy | How close a value is to the truth. | Sales to the nearest pound |
| Interpret | To say what the results mean for the task. | Saturday is the busiest day |
| Query | A question you ask a database. | Sales for each day |
| Database | A store of organised data a program can search. | The sales table |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can choose a way to show data, find a trend or pattern, and say what it means for the task.
Starter: what you already know
Have a go
Starter: what you already know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
About charts on this platform
Important
This platform has no chart builder. Here you make text bars with a query, and describe charts in words. On site you would draw real charts in a spreadsheet or dashboard program.
Four steps
| Step | Ask yourself |
|---|---|
| Read the task | Which trend or pattern is wanted? |
| Choose | Which technique and tool will show it? |
| Represent | Dashboard or graph? How much detail? |
| Review | Does this meet the task, and is it right? |
The cells students fill in are left blank in this preview.
Try it: text bars show a pattern
select dayname(day) as weekday, sales, repeat('#', sales // 2) as bar
from daily
order by day;
-- Try it: change sales // 2 to sales // 3 for a smaller picture.Try it: the change from the day before
select day, sales, sales - lag(sales) over (order by day) as change
from daily
order by day;
-- Try it: which day has the biggest rise?