Cooper-Harper Scale: Is Your UX Design a Disaster?

User experience design impacts product usability, and the Cooper-Harper Scale provides a structured method for evaluation. Specifically, usability testing methodologies leverage the Cooper-Harper Scale to quantify user workload. NASA developed the Cooper-Harper Scale originally for pilot workload assessment, and now it is used in UX design. A high score on the Cooper-Harper Scale indicates a critical need for improvement in the overall user experience.

Deciphering User Frustration: Applying the Cooper-Harper Scale to UX Design

The Cooper-Harper Scale is a valuable tool for evaluating the "handling qualities" of a system – essentially, how easily and effectively a user can interact with it. Originally developed for aircraft handling, its principles are readily adaptable to UX design, allowing designers to quantify user frustration and identify areas needing improvement. An effective article layout explaining this should walk the reader through understanding the scale itself, its application to UX, and how to use it to improve designs.

Understanding the Cooper-Harper Scale

The core of understanding its usefulness lies in grasping the structure of the scale and what each level represents.

The Scale’s Structure

The Cooper-Harper Scale is a decision tree leading to a numerical rating. It consists of a series of questions about task performance and workload that ultimately assign a rating from 1 (excellent) to 10 (intolerable). The questions force an objective analysis of how well a user can perform a task.

• Branching Decision Tree: The scale relies on a series of binary "yes/no" questions that guide the user through the assessment.
• Numerical Rating (1-10): Each path through the decision tree leads to a numerical score, indicating the severity of the handling qualities deficiencies.
• Categorization of Effort and Performance: The scale incorporates factors like workload, accuracy, and control effort.

Deciphering the Numerical Ratings

Each number on the scale has a specific meaning related to usability.

Rating	Handling Qualities	Workload Demand	User Commentary (Typical)
1	Excellent	Negligible	"I can easily accomplish the task with minimal effort."
2	Good	Low	"Easy to use with minimal corrections."
3	Fair	Moderate	"Minor but annoying deficiencies."
4	Minor Modest	Moderate	"Acceptable but some mildly objectionable deficiencies."
5	Minor Objectionable	Considerable	"Requires considerable pilot compensation."
6	Moderately Objectionable	High	"Adequate performance requires extensive compensation."
7	Major Objectionable	Very High	"Controllable but requires excessive workload."
8	Major Deficiencies	Intense	"Unacceptable workload, but could be controlled."
9	Major Deficiencies	Excessive	"Uncontrollable. Significant improvement is required."
10	Catastrophic Deficiencies	Impossible	"Pilot cannot control the system."

Applying the Cooper-Harper Scale to UX

The scale isn’t just for aircraft. Its principles easily translate to websites, apps, and other digital products.

Identifying UX Tasks for Evaluation

First, define the key tasks users will perform within your interface. These tasks become the subjects of the Cooper-Harper Scale assessment. Examples include:

• Creating a new account.
• Searching for a specific product.
• Completing a purchase.
• Updating profile information.
• Contacting customer support.

Adapting the Scale for UX

While the original scale refers to "pilot" and "aircraft," these terms must be contextualized for UX. Key considerations include:

• "Pilot" becomes "User": Reframe the language to apply to a general user interacting with the interface.
• "Aircraft" becomes "Digital Product/Interface": Replace references to the aircraft with the specific website, app, or software being evaluated.
• "Handling Qualities" becomes "Usability": Translate the concept of "handling qualities" to encompass the user’s experience and ability to effectively interact with the interface.
• Task Performance: Focus on the user’s ability to complete the defined UX task.

Example Adaptation: Decision Tree Questions

The questions in the Cooper-Harper decision tree need to be adapted. Here are examples:

1. • Original: "Are satisfactory performance criteria attainable with the aircraft?"
   • Adapted: "Can the user successfully complete the task using the interface?"
2. • Original: "Is adequate pilot compensation required for the aircraft?"
   • Adapted: "Does the user require significant effort or workaround to complete the task?"

Using the Scale for UX Improvement

The true power of the Cooper-Harper Scale lies in its ability to guide improvements.

Gathering User Feedback

The scale should be used in conjunction with real user testing. Observe users as they attempt to complete tasks and then guide them through the Cooper-Harper Scale questions.

• Think-Aloud Protocol: Encourage users to verbalize their thoughts and feelings as they navigate the interface.
• Observation: Pay close attention to user behavior, including mouse movements, hesitations, and errors.
• Post-Task Questionnaire: Supplement the Cooper-Harper Scale with additional questions about user satisfaction and perceived workload.

Interpreting Results and Identifying Problem Areas

Analyze the Cooper-Harper ratings to identify specific problem areas within the user experience.

• High Ratings (7-10): Indicate significant usability issues requiring immediate attention.
• Moderate Ratings (4-6): Highlight areas where the user experience can be improved to reduce frustration and workload.
• Low Ratings (1-3): Suggest that the user experience is generally positive, but there may still be opportunities for optimization.

Iterative Design and Refinement

Use the insights gained from the Cooper-Harper Scale assessment to inform iterative design improvements. Retest the interface after each iteration to validate the effectiveness of the changes. Continuous improvement is key.

So, next time you’re wrestling with a tricky UX problem, remember the Cooper-Harper Scale! Hopefully, this helps you avoid any usability disasters. Good luck out there!