Ordinal Scale

Instructions on how to install LabBench

Represents a categorical rating scale where responses are selected from ordered categories without assuming equal spacing between them.

Availability:

context.Instruments.<OrdinalScaleName>

Properties

Name Type Description
NumberOfCategories int Total number of categories available on the scale.
Categories List[IAnchor] List of category definitions (labels and enabled state).

Methods

Name Signature Description
GetSelectedCategory GetSelectedCategory() → int Returns the currently selected category index.
SetSelectedCategory SetSelectedCategory(category: int) → None Sets the selected category by index. Updates the device state.

Category (IAnchor)

Represents a single category on the ordinal scale.

Properties

Name Type Description
Enabled bool Indicates whether the category is selectable.
Label str Text label describing the category.

Typical usage example

scale = context.Instruments.OrdinalScale

# Read selected category
selected = scale.GetSelectedCategory()

# Set category
scale.SetSelectedCategory(2)

# Inspect categories
for i, c in enumerate(scale.Categories):
    print(i, c.Label, c.Enabled)

Notes / gotchas

  • Category indices are integer-based; valid range depends on NumberOfCategories.
  • No guarantee of equal spacing between categories; treat values as ordered labels.
  • Disabled categories (Enabled=False) may still appear but should not be selected.
  • SetSelectedCategory directly affects the device state and participant interface.
Last modified May 21, 2026: Device server implementation (#1375) (5dd5648d)