These numbers are a result of a quick, and rather unscientific, internet search I did just to confirm what I have read many times about first impressions. Whether the number of seconds is 3 or 60, the bottom line is simple: it does not take long! Add the visuals (how you dress, body language, etc.) and someone has formed a first impression of you before you even get to say hello!
So how do you influence that first impression?
You start by keeping in mind that you want the interviewer to remember you for your skills, experience, ability, willingness to do the job, and enthusiastic, positive, attitude. You do not want be remembered for inappropriate attire or being unprepared. Following are a couple of simple suggestions:
Be well rested and on time. There are no excuses for being late. Allow enough time to check your appearance in the restroom but not so much time that the interviewer feels pressure to start early (approximately 10 minutes).
Take the traditional approach and dress conservatively (suits for both men and women in the U.S.). I have heard some career experts suggest that you “dress a little better than the people you are interviewing with” but unless you know that a more casual dress will not be misinterpreted, stick to conservative. Also, wear clothing that fit well and make you feel good about yourself. You want to feel confident, not self-conscious.
Accessories should be minimal and perfume or cologne should be light. Avoid feeling clumsy or awkward by having to shift around or keep track of multiple personal belongings (purse, portfolio, briefcase, etc.). Carry one item, if possible, that will hold extra resumes, pen, paper, and all your personal essentials (wallet, brush, keys, etc.).
Be courteous and respectful to everyone you meet. Everyone, including the receptionist and administrative support, may be providing their impression of you.
Know as much as possible about the position and the company. Review the job description and be prepared to discuss how your skills and experience match the requirements of the position. Do research on the company mission, vision, customers, challenges, etc. and use that knowledge to answer and ask good questions.
Send a thank you note within 24 hours to all interviewers.
Preparation and confidence are critical to making a good first impression. Paying attention to the details and the basics really does matter.