Scale-Estimation Slider: Player GUI Design

1. Concept: Scale-Only Estimation Input

The game is about estimating scale, not selecting correct answers.
Users should express order of magnitude first, then optionally refine their estimate.

There are no discrete choices and no predefined steps.
Input is continuous and relative.

2. Primary Input: Horizontal Scale Slider

Base Interaction

• A horizontal slider represents a logarithmic scale
• Left = very small
• Right = very large
• The exact numeric value is hidden initially
• Only the unit is shown (e.g. kg, liters, km)

|-----------------------------|
 small                     large

The slider is designed for coarse estimation, not precision.

3. Progressive Precision via Vertical Gesture

Refinement Gesture

• While touching the slider:

• Horizontal movement → changes magnitude

• Vertical movement (upwards) → increases precision
• Vertical movement (downwards) → decreases precision

This allows coarse → fine adjustment in a single continuous gesture.

Precision Levels

Vertical Distance	Precision Mode	Behavior
Near slider	Coarse	Log scale, large jumps
Medium height	Fine	Linear interpolation
High above	Precision	Decimal precision (max 2 decimals)

Rule:

Precision is capped at two decimal places.
This prevents false accuracy.

4. Scale Behavior (Important for Developers)

Scale Type

• Default: logarithmic scale
• Purpose: enable navigation from e.g. 1 → 1,000,000,000 in one motion
• When precision increases:

• The scale locally transitions to linear

• Only within the current magnitude window

This avoids:

• tiny finger movements jumping billions
• meaningless exactness at global scale

5. Visual Feedback

While Sliding

• Show:

• Approximate value

• Unit
• Optional scientific notation at coarse level

Examples:

≈ 10⁶ kg
≈ 1 million kg
≈ 1.23 million kg

Formatting adapts to precision level automatically.

6. Input Rules (Explicit Constraints)

• No keyboard input
• No direct number entry
• No snapping to predefined values
• No minimum / maximum shown numerically
• All values are soft-bounded

• User can overshoot “reasonable” ranges

• Game logic evaluates plausibility, not validity

7. Completion Interaction

• User releases finger → value is locked
• A short confirmation animation reinforces:

> “This is your estimate”

Only after submission:

• The real value is revealed
• Comparison is shown visually (not numerically first)

8. Example Developer-Facing Spec (Condensed)

InputComponent: ScaleSlider

- Axis: Horizontal (logarithmic)
- Gesture:
  - X-axis: magnitude selection
  - Y-axis: precision modulation
- Precision:
  - Dynamic
  - Max 2 decimal places
- Units:
  - Always visible
- Values:
  - Continuous
  - No discrete steps
- Purpose:
  - Express scale intuition, not exact knowledge

9. Design Philosophy (One-liner)

“The user should feel like they are feeling out the size of the world, not entering a number.”