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A small journal where UX, code, and everyday life meet.

#ux clinic#vending machine#signage & feedback#feedback & status

Simple Water, Complex Flow

Story from the field

A small everyday moment that didn't feel quite right.

A small everyday moment that didn’t feel quite right.

At an international airport, I stopped by a vending machine that sells bottled water.

It looked simple enough: just one type of water, lined up in rows behind a glass panel. The payment area, however, was placed quite high on the top-right of the machine.

There was also a paper sign taped below it, roughly at eye level, to explain where to tap a card. The problem was that the sign looked almost like a QR code or a typical tap symbol.

The arrow on the sign was very small, and the large illustration in the middle looked like the actual place to touch. Naturally, I tried tapping on the printed symbol first. Nothing happened.

Only after staring at the machine for a while did I notice a faint, real touch area slightly above the sign. When I tapped there, the machine finally accepted my payment.

The overall flow was also unclear. You were supposed to:

  1. Choose a number from a grid of small buttons, even though all bottles were the same water.
  2. Tap your card in the hidden touch area.
  3. Wait several seconds with no clear feedback.
  4. Watch the bottle appear from an unexpected place.

The first time I went through this, each step felt a bit like solving a small puzzle rather than simply buying water.

Later, I came back to buy another bottle and saw an older man doing exactly what I had done: tapping directly on the printed illustration, then staring at the machine, unsure if anything was happening.

I showed him where to tap, how to enter the number, and then we waited together until the machine finally started moving. I could clearly see the same uncertainty I had felt on his face.

The machine worked. But the amount of guessing, waiting, and double-checking felt much higher than it needed to be for something as basic as buying a bottle of water.

Frictions & Possible Tweaks

Where the experience rubs, and small moves that could help.

1
Qfriction

The “Tap here” sign invites you to tap the wrong place

The paper sign is trying to help, but its layout does the opposite:

  • The biggest, most noticeable element is an illustration that looks like a tap target.
  • The actual touch area is higher up, faint, and easy to miss.
  • The arrow is small, so it doesn’t clearly connect the illustration to the real contact point.

As a result, many people naturally tap the illustration first. Only after trial and error do they discover where the real touch area is.

↓
+Possible Tweaks

(no title)

On-the-ground idea (today)

  • Redesign the paper sign so that the arrow is the hero: big, bold, and pointing directly at the real touch area.
  • Use simple text like Tap card here next to the arrow, rather than relying on a decorative symbol.
  • Keep any illustration small and secondary, so it supports the arrow, instead of competing with it.

Machine-level idea (if you can redesign the machine)

  • Move the touch area closer to eye level and make it visually clear (for example, with a contrasting color frame or light).
  • Add immediate feedback when a card is read: a short sound, a light, or a brief message such as Payment received.
  • Consider integrating the card reader and its label into one unified visual element, instead of separating them into “machine hardware” and “paper sign”.
2
Qfriction

The order of steps (number → tap) feels like a small puzzle

The machine expects users to:

  1. Pick a number from a panel of small numeric buttons.
  2. Tap their card in the separate touch area.

However, the layout doesn’t clearly communicate this order:

  • There are many numbers even though all bottles are the same water.
  • The numeric panel and the touch area feel disconnected.
  • The product grid, numbers, buttons, and sign all compete for attention.

For a first-time user, it can feel like a guess-the-ritual mini-game rather than a simple purchase.

↓
+Possible Tweaks

(no title)

On-the-ground idea (today)

  • Add a small step-by-step label near the numeric panel and sign, such as:
  1. Press the number you want.
  2. Tap your card here.
  • If all bottles are the same water, highlight that fact:

All numbers are the same water. Press any number, then tap your card.

This removes the mental burden of picking “the right slot”.

Machine-level idea (if you can redesign the machine)

  • Reduce the number of choices when all products are identical: for example, only one or two large buttons for water.
  • Group the numeric panel and touch area into a clear flow with visual grouping, arrows, or a small screen that guides users through “Step 1 → Step 2”.
  • Use a small display that confirms the selected product before payment:

You selected: Water — 500ml.

3
Qfriction

The long, silent wait feels like something might be broken

After entering the number and tapping the card, the machine pauses for a few seconds before anything moves. In that pause:

  • Users don’t know if their card was detected.
  • They don’t know if they pressed the number correctly.
  • They’re left wondering whether they’ve just wasted their money.

Only after that quiet pause does the machine finally come to life and deliver the bottle, often from a place that isn’t clearly visible from the front.

↓
+Possible Tweaks

(no title)

On-the-ground idea (today)

  • Add a simple message near the sign, such as:

After tapping, please wait a few seconds while we prepare your drink.

  • If possible, place a small sticker near the drop slot with:

Your bottle will come out here.

so users know where to look and don’t have to scan the machine in confusion.

Machine-level idea (if you can redesign the machine)

  • Show a short in-progress state after payment, even with a basic display:

Processing your order…

or a simple progress animation.

  • Trigger visible motion or light immediately after payment, even if the bottle drops a few seconds later. This reassures users that the machine is working.
  • Make the final output point more visible (lighting, framing, or a small icon), so users instantly know where their drink will appear.

Key Takeaways

A quick keyTakeaways you can reuse in your own work.

  • Even when the hardware and payment logic can’t easily be changed, signage and step labels can dramatically reduce user confusion and emotional load.
  • For basic tasks like buying water, users shouldn’t have to solve a puzzle. The path from I’m thirsty to I’m holding a bottle works best when each step is clearly visible and easy to confirm.
  • When a flow involves waiting or delayed movement, a tiny bit of feedback (we’re working on it) makes the experience feel safer and more trustworthy.
  • Small, layered improvements — at the machine level and at the paper sign / sticker level — can turn an anxious, uncertain moment into a simple everyday interaction people don’t have to think about twice.

SOLA Journal is a publication by SOLA Studio.