Mistakes in tasks during a tree testing session can significantly impact the validity of your results. Here are some common errors to avoid:

• Using exact category labels: This gives away the answer. For example, asking "Find information about pet adoption" directly leads users to the "Pet Adoption" category. Instead, rephrase it to avoid direct hints.
• Overly complex scenarios: Long, detailed stories can distract users. For instance, "You are adopting a pet and need to know the legal requirements and procedures for pet adoption in your area" is too lengthy and may cause users to miss crucial details. Keep it simple and to the point.
• Unclear or vague instructions: Avoid tasks that don't clearly direct users. For example, "Find important information about pets" is too broad and doesn't guide the user effectively.

A better task about pet adoption would be, “You are thinking of adopting a pet. Check if there are any resources on this site that can help you understand the process.”