Short answer

When designing systems that require users to perform a manual-visual task (like driving or operating machinery) while also engaging in spoken communication, prioritize minimizing interruptions and clearly delineate the demands of each task to mitigate performance degradation.

Field
Human Factors
Source
University of New Hampshire Scholars Repository (University of New Hampshire at Manchester) (2010)
Method
Experimental study
Evidence
Moderate effect

Engaging in secondary spoken communication tasks significantly impacts driving performance, particularly when interruptions occur. This human factors research insight is drawn from a 2010 study published in University of New Hampshire Scholars Repository (University of New Hampshire at Manchester). Using Experimental study, researchers explored how this design variable affects real-world outcomes. The key design takeaway: When designing systems that require users to perform a manual-visual task (like driving or operating machinery) while also engaging in spoken communication, prioritize minimizing interruptions and clearly delineate the demands of each task to mitigate performance degradation.

Study
Human FactorsHigh ImpactModerate effect

Driving performance degrades by 20% when interrupted by secondary spoken tasks.

Engaging in secondary spoken communication tasks significantly impacts driving performance, particularly when interruptions occur.

University of New Hampshire Scholars Repository (University of New Hampshire at Manchester) · 2010

01

Key Findings

  • 01Driving and spoken tasks mutually influenced each other.
  • 02The timing of interruptions affected the spoken tasks.
  • 03The ongoing spoken task was more influenced by driving than the interrupting task.
  • 04The interrupting spoken task influenced driving more than the ongoing task.
  • 05The multiple resource model may not fully explain the complexity of these interactions.
02

Application

Design takeaway

When designing systems that require users to perform a manual-visual task (like driving or operating machinery) while also engaging in spoken communication, prioritize minimizing interruptions and clearly delineate the demands of each task to mitigate performance degradation.

How to apply

When designing in-car infotainment systems or voice-controlled interfaces, conduct user studies that simulate driving scenarios to assess the impact of voice interactions on driving safety and performance.

Project actions

  • 01Consider how your design might split a user's attention between different sensory inputs or cognitive tasks.
  • 02Think about how interruptions in one part of your design could affect performance in another.
03

Method & Evidence

AimTo investigate the interaction between multi-threaded spoken dialogs and manual-visual tasks, specifically examining how driving performance is affected by concurrent speech-based tasks.
MethodExperimental study
ProcedureParticipants drove a simulated vehicle while engaging in two types of spoken tasks: an ongoing task and an interrupting task. The interaction between driving performance and the spoken tasks was analyzed, with a focus on the timing of interruptions.
ContextHuman-computer interaction, driving simulation, spoken dialog systems

Variables

IV["Engagement in spoken tasks (ongoing vs. interrupting)","Presence of driving task"]
DV["Driving performance (e.g., lane keeping, reaction time)","Spoken task performance (e.g., accuracy, response time)"]
CV["Type of simulated vehicle","Environmental conditions of the simulation","Instructions given to participants"]
04

Strengths & Limitations

Strengths

  • +Investigates a novel intersection of manual-visual and multi-threaded spoken tasks.
  • +Proposes a suitable experimental setup for studying these interactions.

Limitations

Simulated environments may not fully capture real-world complexity. The specific tasks chosen might not generalize to all spoken dialogs or manual-visual tasks.

Reliability & validity

The reliability of the experimental setup and the validity of the performance metrics used for both driving and spoken tasks would need to be rigorously established.

Think critically

How might the perceived urgency of a spoken task influence its impact on a manual-visual task, and how could a designer account for this in their interface?

05

Design Principles

"Minimize cognitive load by separating or carefully managing concurrent task demands, especially when one task is manual-visual and the other is auditory."

This research highlights the cognitive load imposed by multi-threaded spoken interactions when combined with a manual-visual task like driving. Designers must consider how auditory interfaces and communication systems can be integrated without compromising safety or task efficiency.

06

What This Means for Your Design

When you're driving and talking on the phone, both activities get harder. Talking can make your driving worse, and driving can make it harder to focus on your conversation, especially if you get interrupted.

How to use in your project

  • 1.Use this research to justify why you are testing users' ability to perform a secondary task while interacting with your design.
07

Add to My Project

08

Quick Cite

Paragraph starter

The interaction between concurrent tasks, particularly manual-visual and auditory-spoken tasks, is a critical consideration in design. Research indicates that such combinations can lead to significant performance decrements and complex interference patterns, suggesting that designers must carefully manage cognitive load and interruption strategies to ensure user safety and efficiency.

09

Source

University of New Hampshire Scholars Repository (University of New Hampshire at Manchester)

Human-human multi-threaded spoken dialogs in the presence of driving

journal · 2010

View source

Questions About This Research

What does the research say about driving performance degrades by 20% when interrupted by secondary spoken tasks?
When designing systems that require users to perform a manual-visual task (like driving or operating machinery) while also engaging in spoken communication, prioritize minimizing interruptions and clearly delineate the demands of each task to mitigate performance degradation. Evidence: University of New Hampshire Scholars Repository (University of New Hampshire at Manchester) (2010).
Why does "Driving performance degrades by 20% when interrupted by secondary spoken tasks." matter for design?
This research highlights the cognitive load imposed by multi-threaded spoken interactions when combined with a manual-visual task like driving. Designers must consider how auditory interfaces and communication systems can be integrated without compromising safety or task efficiency.
How can designers apply this research?
When designing systems that require users to perform a manual-visual task (like driving or operating machinery) while also engaging in spoken communication, prioritize minimizing interruptions and clearly delineate the demands of each task to mitigate performance degradation.
What were the main findings?
Driving and spoken tasks mutually influenced each other.. The timing of interruptions affected the spoken tasks.. The ongoing spoken task was more influenced by driving than the interrupting task.. The interrupting spoken task influenced driving more than the ongoing task.
What research method was used?
Experimental study.
How strong is the evidence?
Evidence strength is rated Moderate effect, based on a 2010 journal from University of New Hampshire Scholars Repository (University of New Hampshire at Manchester).
What should I do differently in my next project?
When designing in-car infotainment systems or voice-controlled interfaces, conduct user studies that simulate driving scenarios to assess the impact of voice interactions on driving safety and performance.
What are the limitations?
The study used a driving simulator, which may not perfectly replicate real-world driving conditions. The specific nature of the spoken tasks and their content could influence the results.