Learnosity customers design Activities across a wide range of assessment scenarios, from simple practice quizzes to complex, higher-stakes exams with rich multimedia content. Item count, Item complexity, and payload size all affect performance. With careful design, Activities can initialize quickly, load efficiently, and remain responsive for learners.

This article outlines Learnosity’s guidelines for reliable Activity design and applies to the following Activity types:

• Standard Activities with sections
• Random by group Activities

Items per Activity

From v2026.2.LTS, the default maximum number of Items per Activity is 300, and this limit applies to both authoring and delivery.

The same delivered Item limit applies to random by group Activities. Random by group Activities can deliver up to 300 Items selected from a candidate pool of up to 1000 Items, divided across a maximum of 50 groups.

Activities with up to 300 Items are expected to perform reliably under typical usage conditions. This guidance replaces previous uncapped behavior and is based on extensive performance testing across representative content types and usage conditions, helping provide greater reliability and consistency for learners.

Exceeding the default maximum prevents Activities from being saved via the Author API or Data API. Assessment delivery will also fail to initialize through the Items API.

When upgrading from earlier LTS versions, review any existing Activities that exceed these limits and split them into smaller Activities where appropriate. If an existing use case cannot reasonably be restructured, speak with your Learnosity Customer Success Manager to discuss possible approaches.

Key factors affecting performance

1. Item count

Item count alone does not reliably predict performance. Two Activities with the same number of Items can behave very differently depending on Item complexity.

2. Item complexity

Item complexity can significantly affect performance. Complexity increases when Items include:

• Multiple Questions within a single Item
• Long or rich text content
• LaTeX-based math equations
• Images, audio, or video Features

3. Payload size and rendering

Payload size is a primary factor affecting performance. Larger payloads can increase:

• Load times
• Memory usage
• Network transfer time

Some content can also create heavy rendering demands independently of payload size. For example, Activities with substantial LaTeX-based math content may require additional processing during rendering.

Even with a moderate Item count, large payloads or rendering-heavy content can reduce Activity performance.

Comparing simple and complex Activity designs

Example: Simple Activity design

• Item count: up to 300
• Structure: One Question per Item
• Content: Short text, minimal formatting
• Media: None or small, optimized images
• Interactions: Standard Question types (e.g., MCQ, Match list)

Performance characteristics:

• Predictable payload size
• Lower processing overhead
• More consistent performance across devices and network conditions

Example: Complex Activity design

• Item count: 200 - 300
• Structure: Multiple Questions per Item
• Content: Long passages, rich formatting
• Media: Multiple images/audio/video per Item

Performance characteristics:

• Higher Item complexity increases payload size
• Larger payloads
• Increased processing time
• Higher risk of performance issues even within default limits

Best practices

• Keep Items simple: Use one Question per Item and avoid complex or deeply nested structures.
• Minimize payload size: Reduce unnecessary content, formatting, and media, keeping in mind each Item adds to the API request/response payload.
• Optimize media: Compress images, audio, and video, and avoid multiple large files in a single Item.
• Test with realistic content: Validate Activity performance using representative Item structures, volumes, media, and learner environments.
• Monitor and adjust: Track performance during development and revise Item count or complexity as needed.