Webbo3 Power BI · Cohort 1 · Day 15 of 16
Day 15: Slicers, Drill-through and Dashboard Storytelling
Letting the reader ask their own questions, and laying a page out so it tells one story.
By the end of today you can
- Choose the right slicer style: list, dropdown, tile or date range
- Keep slicers in step across pages with Sync slicers
- Control which visuals a slicer or a click affects with Edit interactions
- Build a drill-through page that opens on the station a reader right-clicks
- Lay a page out so it reads as one story, from headline to detail
Assignment 3 is due today, and your pod's report pages are being built. Today is about the reader: how they move around your report, and what they understand in the first ten seconds.
1. Slicers
Definition
A slicer is a visual whose only job is filtering: the reader clicks a value and every other visual on the page recalculates for it. It is the filter pane brought onto the page, where the reader can see it.
Real-Life Example
The filters on a shopping app: size, colour, price. You tick "Size 42" and every product on the screen changes. Nobody reads a manual to use them, because they are right there.
Types
| Style | Set in Format, Slicer settings | Best for |
|---|---|---|
| Vertical list | Style: Vertical list | A few values the reader needs to see at once |
| Dropdown | Style: Dropdown | Many values (17 attendants) where space is tight |
| Tile (buttons) | Style: Tile | Two to five values, such as years or regions |
| Between (date range) | A date column, Style: Between | Any date range the reader chooses |
- Multi-select: Ctrl-click picks several values. Turn on "Select all" in Selection if readers want an easy way back.
- Single select: Format, Selection, Single select. Use it when two values at once make no sense.
- Clear it: the eraser icon at the top of a slicer clears it. Tell your reader it is there.
Picture the shopping app's filter bar: always visible, obvious to click, easy to clear.
2. Sync Slicers
Definition
Sync slicers makes one slicer control several pages. Pick 2024 on the Overview and the Stations page is already on 2024 when the reader gets there.
Real-Life Example
Choosing your country once on a website, and every page after that shows prices in naira. You would be annoyed to choose it again on every page.
Click path
Sync without Visible is useful: the page follows the year chosen elsewhere without showing a second slicer.
3. Edit Interactions
Definition
By default, clicking a bar in one chart filters every other visual on the page. Edit interactions lets you choose, for each pair of visuals, whether the click filters, highlights or does nothing.
Real-Life Example
A headline card that should always show the whole business, even while the reader clicks around the charts below it. You switch its interaction off so it never moves.
Click path
| Icon | Effect |
|---|---|
| Filter | The other visual shows only the clicked value |
| Highlight | The other visual keeps everything, with the clicked part darker |
| None | The other visual ignores the click |
If a visual in your Assignment 3 does not follow the slicer, this is where to look: select the slicer, Edit interactions, and set that visual to Filter.
4. Drill-through
Definition
A drill-through page is a detail page about one thing, such as one station. The reader right-clicks that station anywhere in the report, chooses Drill through, and lands on the page filtered to it. A back arrow takes them home.
Real-Life Example
A class list with a name you can click to open that student's report card. The list is the overview; the report card is the drill-through.
Build a drill-through page
% of All Stations still works on the detail page because it uses ALL ( Stations ) from Day 11. The drill-through filters the station; ALL looks past it for the whole.
Picture the class list and the report card: the list stays tidy because the detail lives one click away.
5. Dashboard Storytelling
Definition
Storytelling means the page has one message, and its layout leads the eye to it: headline first, evidence next, detail last. A reader who stops after five seconds still leaves with the message.
Real-Life Example
A newspaper front page. The headline tells you what happened, the photo shows it, the first paragraph explains it, and the detail is further down for those who want it. Nobody reads the bottom of the page first.
The Rules
| Rule | In practice |
|---|---|
| Read like a Z | People read top left, across, down, across. The most important card goes top left |
| One question per page | Overview, Stations, Products: not everything on one page |
| Headline cards on top | 3 to 5 cards across the top: the numbers that matter most |
| Evidence in the middle | The chart that proves the headline: the trend or the ranking |
| Detail at the bottom | Tables and matrices, for the reader who wants the figures |
| Titles are findings | "GRA earns the most", not "Total Revenue by Station" |
| Line things up | Format, Align, and Distribute; equal gaps; the same card size |
| Few colours | One main colour; a second only to point at something |
Take your Assignment 3 page and hold it to the rules. Is the most important card top left? Does every title say a finding? Are the gaps equal? Change three things, then ask a classmate what the page is telling them after five seconds.
Do This Now
- Change your Year slicer to Tile, and add a date range slicer on a second page.
- Sync the Year slicer across every page.
- Set Edit interactions so the headline cards ignore the bar chart.
- Build the Station Detail drill-through page and try it from the overview.
- Rearrange your overview page to the storytelling rules.
- Hand in Assignment 3, then work on the Pod Project with your pod.
Checkpoint
Q1. Eighteen attendants in a slicer on a crowded page. Which style?
Dropdown. It takes one line of space until it is opened.
Q2. A reader picks 2024 on page 1 and page 2 still shows both years. What is missing?
Sync slicers: the Year slicer is not synced to page 2.
Q3. How does a reader get to a drill-through page?
Right-click a value of the drill-through field (a station) in any visual, then Drill through and the page name.
Q4. What goes top left on a page, and why?
The most important number, because that is where people start reading.
Tick Before You Move On
- ☐ I used at least two slicer styles and know when to choose each
- ☐ My Year slicer is synced across pages
- ☐ I set at least one interaction to None on purpose
- ☐ My Station Detail page opens filtered from a right-click
- ☐ My overview page reads headline, evidence, detail
Quick Recap
Slicers let the reader ask; choose list, dropdown, tile or date range by the values. Sync slicers keeps pages in step; Edit interactions decides who reacts to a click. Drill-through keeps the detail one right-click away. A story page: headline top left, evidence in the middle, detail below, titles that say findings.
Final Scenario
The owner of Webbo Oil opens your report with no training at all.
She reads the headline cards, taps 2024, sees GRA Filling Station at the top of the ranking, right-clicks it, and is looking at its attendants twenty seconds later. She never asked you how to use it.
The best report needs no instructions, and that is designed, not lucky.
Next, Day 16: Pod presentations. Ten minutes, in front of the client.