Don’t joke, indulge in sarcasm, flirt, or betray your own nervousness

Maintain a professional, neutral persona

Keep yourself "small" in relationship to the participant. Sit slightly back from the participant, in a chair that is lower.

Avoid wearing heavy perfume or aftershave. The participant may have allergies to the odor or find it distracting.

Don’t wear suggestive, revealing, or tight, uncomfortable clothes.

• Don’t bias the participant

Don’t betray your own views or opinions of either the participant’s level of skill

Don’t let the participant become aware of any bias you may have about the product.

• Avoid interactions with the user that can shift the focus from the user’s domain to the designer’s

Don’t expect the user to tell you how to fix problems

Don’t expect the user to answer other design questions

Always keep the focus of attention on the user, not yourself. Avoid "I" statements and long explanations of how the system works.

Stay in the relationship with the participant. Don’t worry about the next question you are going to ask.

Write down design ideas so that you don’t need to worry about forgetting them after the test.

• Don’t let yourself get impatient!

When the participant seems to have a problem, they can often unravel it without your help.

When you feel you should jump in, count to ten first.

If you jump in too soon, you lose valuable data and they become dependent on your help.

Don’t ask "Do you like that dialog box?" but "Did that dialog box help you reach your goal?"

• Focus on questions, not answers
• Explore user thinking in a neutral way

Don’t be too quick to assume that the user is lost or having a problem.

Don’t say, "What is your problem here?," but ask, "What is your goal?" or "What are you thinking you should do here?"

• Don’t betray your own interests or point of view by your comments, emphasis, "waking up" and getting interested, showing in facial expression or vocal tones that you disagree
• Good user-focused questions:

Echoing sets up a social dialog and reinforces social conversation expectations: they say something, you repeat it, they say the next thing because that is what is expected in conversation.

• Don’t put words in their mouth, or offer interpretations

If they say, "I’m not sure what to do here," don’t say, "So you are confused because the menu bar is unclear?"

If they say, "That didn’t happen like I expected, don’t ask, "So you thought that the task menu would be displayed here?"

"And you were expecting. . .?"

"And your goal is . . .?"