Overview

Objective: Evaluate HCI (human-cat interaction) during tummy rub
Project Type: Personal, Heuristic Evaluation
Methods: Task analysis, heuristic evaluation

Intro

Heuristic Evaluations are a great way to gain general insight into the usability of a product and identify potential shortcomings. The Jakob Nielson (deity of all things usability) list of 10 heuristics has held up to nearly a quarter century of use. While this list is typically applied to more traditional user interface design, I find it is effective for a wide variety of situations. Human Cat Interaction is an area long riddled with usability problems. This usability issue is rarely a deal breaker: Cat usership has increased at a steady rate over the last decade with more people using cats than ever before. Still, a positive user experience does not guarantee good usability. Anecdotal evidence in the form of memes and web comics indicates that tummy rubs are a frequently identified usability issue. My aim is to use Nielson Heuristics to identify failings in the interaction process and design solutions to improve usability and user experience.

Task Analysis

Before we get to the Heuristic Evaluation, I’d like to outline the task analysis of this interaction.

  1. Interaction is initiated. Can happen in several ways:
    • Cat indicates desire for tummy rub
      • In the form of rolling onto their back and alerting the human of this desire
      • In an ambiguous form: meows, aggressive stares, other unknown indications
    • Human independently chooses to initiate tummy rub because:
      • Human believes cat desires tummy rub
        • Possibly correct assumption
        • Possibly incorrect assumption
    • Human wants to rub tummy for other, unknown reason
  2. Interaction commences:
    • Cat approaches human
    • Human approaches cat
    • Some form of mutual human-cat collision
  3. Human begins tummy rub
  4. Cat responds
    • Positively
      • Indicates consent through common methods of purrs, further tummy exposure, or spastic flailing
      • Indicates consent in uncommon or misinterpreted way
      • Biting
      • Attacks hand
      • Struggles away from human hand
    • Neutral
      • Indicates neither consent or displeasure
    • Negatively
      • Indicates displeasure
      • Biting
      • Attacks hand
      • Struggles away from human hand
      • Indicates displeasure in the form of non-indication (does not react)
  5. Interaction continues:
    • Cat continues to demonstrate previous state (see step 4)
    • Cat changes state from step 4
    • Human ends contact before cat reevaluates state
  6. Interaction Ends:
    • Cat ends interaction
      • Rescinds tummy exposure (either due to behavior of human or personal reasons)
      • Aggressively with claws or teeth
      • Casually by rolling over or wandering away
    • Human ends interaction
      • Due to lack of desire to continue pets
      • Due to behavior or feedback given by cat
    • Mutual ending of interaction
      • Cat and human mutually respond to the behavior of the other
      • Reason unrelated to interaction

It’s important to note that this interaction can influenced by a variety of factors and could differ each use because of that. These factors include the personality of the human, the personality of the cat, and environmental factors that may influence either the cat, the human, or both.

Heuristic evaluation

  1. Visibility of System Status: Needs improvement. System status is occasionally present (purring), but not reliable or consistent.

  2. Match Between System and the Real World: The human user is often unfamiliar with the communication tactics of the cat. A comparable experience with another human rarely exists.

  3. User Control and Freedom: The user is sometimes free to exit with no risk, but other times a quick exit may be impeded by the sudden onset of claws to the hand. There is no support for an “undo” or “redo” type action. Mistakes can end with significant consequence.

  4. Consistency and Standards: General cat interaction conventions hold to the extent that you can rely on them being consistently inconsistent. What indicates positive feedback in one cat may result in disaster with another cat or even from the same cat on a different interaction.

  5. Error Prevention: The system does little to prevent errors. Users are given no confirmation option before an error occurs. While the system provides some feedback to indicate an error may be approaching, it is difficult for the user to pinpoint the exact point of error until it has already occurred. Error prevention occasionally occurs when the system abruptly ends the interaction as the user approaches an error.

  6. Recognition Rather than Recall: Very little recall is required. The system operates mostly on recognition, but these prompts aren’t always noticed by the user.

  7. Flexibility and Efficiency of Use: The system excels here for frequent users, which can more easily recognize system status and avoid errors. Novices aren’t excluded, but it can be difficult for first time users and additional flexibility could be achieved without compromising expert user experience.

  8. Aesthetic and Minimalist Design: The system typically only provides essential information; almost to a fault. Occasional irrelevant information is provided at times, but more frequently, the user entirely lacks the information they need.

  9. Help Users Recognize, Diagnose, and Recover from Errors: This system is rarely user friendly in this regard. Error messages are frequently unclear and a constructive solution is rarely given. Users frequently are left knowing they made a mistake, but are uncertain of what specifically went wrong.

  10. Help and Documentation: Help and documentation only exist from outside sources. This information is easy to locate, but can be overwhelming due to its abundance and rarely focuses on the user’s specific problem.

Strengths

  • Minimalist design
  • Recognition over recall

Neutral

  • Help and documentation
  • Match between the system and real world.

Weaknesses

  • Helps users recognize, diagnose, and recover from errors
  • Flexibility and efficiency of use
  • Error prevention
  • Consistency and standards
  • User control and freedom
  • Visibility of system status

Summary

This system has major weaknesses in allowing the user to understand what the system is doing or predict what the system might do in the future. This results in significant potential for human error and difficulty in continuing use after an error is made. Improvements to visibility of system status and consistency and standards would be the easiest to implement and have the biggest impact in resolving the other heuristic weaknesses. By implementing standardization, the system could prevent errors, give a clearer system status, allow greater user control, and be easier for novice users to navigate, which could increase flexibility and efficiency of use. Paired with standardization, a more visible system status will also assist in error prevention, increase user control, and make it easier for novices to use without compromising efficiency for experience users.

The cost to adding new features to the system is significant and not guaranteed to be effective, so in this case existing features can be reworked to achieve better usability. The system is skilled at a wide range of vocalizations and has shown success in displaying system status clearly to non-human user groups using body language. Unfortunately, this requires the user to learn some communication that may be unfamiliar to them. A brief one-time demo should provide enough information for the user to proceed confidently and improve their skill as they use the product more. This demo will need to be brief enough to avoid deterring new users. Updates in vocalization cues could be complex and the engineering team will need to consult on the feasibility of that proposal.