Module 6: Adding Interaction

Make your Module 3 visualization explorable. Layer in one interaction so the decision-maker can answer their own follow-up question inside the chart, without coming back to you.

1
Quick Intro
2
Guided Practice
3
Applied Task
4
Quick Refinement
1

Quick Intro

~3 min
1

What is interaction?

30 sec
Interaction = a control on the chart that lets the audience steer it. A dropdown that changes what's shown. A hover that reveals the exact number. A click that drills into a sub-region. The audience is no longer just reading the chart — they're using it.
2

Why it matters

30 sec
A static chart answers one question. A decision-maker almost always has follow-up questions: "What about my district?", "What about just last year?", "What if we exclude that outlier?" Without interaction, every follow-up means you go away and make another chart. With interaction, the audience answers their own follow-ups in seconds.
Goal: the chart serves the next decision, not just the first one.
3

How it fits into data storytelling

30 sec
A data story has four pillars. Interaction is the fourth.
1. Data the numbers
2. Visualization the chart
3. Narration the framing
4. Interaction the controls
If you ship a chart without interaction, the audience can read your story but can't probe it.
4

Small example

45 sec
Same chart, same data — once without interaction, once with.
Static

Cycling trips in Munich, 2018–2023.

bar chart, all districts pooled
22% increase, 2018→2023

City council member: "Does the trend hold in my ward?" → has to ask you for another chart.

+ Filter

Cycling trips, with district dropdown.

bar chart + ⌄ District: [All]
same 22% line by default
switch to "Schwabing": 31%
switch to "Bogenhausen": 8%

Same council member, 3 seconds later: "OK, mine is at 31% — even better than the citywide trend."

5

Five patterns to choose from

1 min
Most useful interactions in mobility data stories fall into five buckets. Pick one — usually one is enough.

Filter

Narrow what's shown (year, district, mode of transport).

"Show only Bogenhausen."

Hover-detail

Mouse-over reveals exact number, source, or method note.

"2023 figure: 3,142 daily trips (Destatis)."

Drill-down

Click an element to zoom into a sub-view.

"Click a district to see street-level."

Brush / range

Drag to highlight a sub-segment of the data.

"Drag across summer months only."

Animation / timeline

Play through years or scenarios.

"Press play: watch the map fill in 2018→2023."
6

When NOT to add interaction

30 sec
Interaction is overhead. Skip it when:
  • The audience has under 5 minutes (they won't learn the controls)
  • There's only one decision being made (a static chart that answers it wins)
  • The output medium is print or PDF (interaction is impossible)
  • The chart already shows the answer at a glance
A static chart that answers the question in 5 seconds beats an interactive chart that takes 30 seconds to learn.
Continue to Module 7 →
2

Guided Practice

~3 min
1

The starting chart

30 sec
Picture a Module-3 chart: bars showing total annual cycling trips in Munich, 2018–2023. One headline: "Cycling trips up 22% over five years."
2018 ████████ 142k
2019 █████████ 156k
2020 ████████████ 198k
2021 ███████████ 187k
2022 ████████████ 201k
2023 █████████████ 217k
It answers the city-wide question. Now the council member asks: "What about my district?" — and we've got nothing.
2

Pick the right pattern

45 sec
Five candidates. Walk through them quickly for this question:
  • Filter — by district. The follow-up is literally "filter to my district." ✓ Strong match.
  • Hover-detail — exact numbers on each bar. Useful, but doesn't answer "my district".
  • Drill-down — click year → show districts that year. Works, but more clicks for the same answer.
  • Brush — drag a year range. Doesn't address district question.
  • Animation — too theatrical for one council member's question.
Choice: Filter by district. Smallest change to the chart that answers the audience's actual follow-up.
3

Spec the interaction (no code needed)

1 min
Specify the interaction in plain language — that's enough for a designer, developer, or yourself in a Tableau worksheet to build it.
Spec

Pattern: Filter

Control: Dropdown above the chart, labeled "District", default "All districts".

Options: 25 Munich district names, plus "All".

Effect: When changed, all bars recalculate to show only trips in the selected district. Headline updates to "Cycling trips in [district], up X% over five years."

Follow-up it answers: "Does the citywide trend hold in my district?"

No code. No chart library decision. Just a precise English spec your audience can verify before any pixel is drawn.
3

Applied Task

~5 min

Spec one interaction for the Module 3 chart you described above. Pick one pattern, one audience, one follow-up question. Keep it small — one interaction usually beats three.

If unsure, default to Filter — it's the most common and the cheapest to build.

Different audiences need different interactions. A council member wants Filter by their own district; a researcher wants Brush to slice their own range.

Start with "What about…" or "Does it hold…" or "Why does…". One specific question the audience would otherwise ask you for a new chart.

In plain English. No code. A developer or designer should be able to build it from your sentence.

4

Quick Refinement

~2 min
1

Review your spec

30 sec
Here is the interaction you specified. Read it as your audience would.
Save the spec in Applied Task first — your summary will appear here.
2

Write your one-sentence commitment

1 min
Lock in your interaction plan in one sentence. This is what Module 7 will pull into your final story brief.
Your one-sentence commitment:
3

Complete Module 6

30 sec
Save your commitment to lock it into your story.