You’ve done your homework, located and researched the company of your dreams, updated your resume and aced the first interview for a perfect position. You want this job, feel uniquely qualified for it and would even receive a big raise if you land it.

Now comes that all-important second interview with the decision maker. From shining your shoes to getting a haircut, you’ve orchestrated every detail to make the best possible impression.

But have you? By keeping your eye on that prized position, you may have overlooked the importance of pleasing the gatekeeper -- the person standing between you and professional glory.

Here’s where your communication and strategizing skills can truly pay off. Suppose you could quickly size up your interviewer and peer inside his head to learn what he considers important and how he makes decisions. You’d then be able to tailor your presentation to the way he prefers to hear and learn. In effect, you’d be "speaking his language" while describing your strengths.

In fact, having this skill would be invaluable in every encounter -- from job interviews to contract negotiations to co-worker interactions -- because your ideas and messages would be understood and well-received.

But how can you determine how someone prefers to receive information? The most basic way is by knowing their "personality type." Based on a host of observable clues about personality type, you can "speed-read" a person’s style, key values and motivations. Once you understand these signs, you can adjust your style and deliver your message in a way that’s comfortable to your listener, focusing on the things that are important to him. In effect, being able to speed-read others allows you to achieve the ultimate communications goal: to "speed-reach" them.

Naturally, having the ability to speed-read hiring managers provides candidates with a critical edge in interviews, says Sarah McNaughton, president of CM of New England Outplacement International, a career management firm in East Hartford, Conn.

"In the interview process, you never get a second chance to make a first impression," she says. "Being able to understand the interviewer’s personality -- what he or she’s like and is looking for -- gives the candidate a wonderful advantage."

The personality-type theory, which identifies 16 different personality types, was originated by Swiss psychologist Carl Jung and the mother-daughter team of Katharine Briggs and Isabel Briggs Myers. Using personality type measurements to size up others has become more prevalent in the past 15 years. For instance, lawyers have adopted this approach to predict and influence jurors’ behavior in numerous high-profile civil and criminal cases. By observing a variety of clues, such as appearance, demeanor, energy level, language, occupation, interests and body language, you can identify which of the 16 types you’re dealing with during a job interview.

We’ve all experienced the ease and joy of being "in sync" with someone. Often the reason we feel comfortable and communicate so well with the other person is that we’re most like them. In terms of personality type, this means that we share many of the same "preferences" on each of the four dimensions that make up a person’s type. These shared qualities help us form communication "bridges" that can be crossed easily. On the flip side, when someone is different from us, we have to be aware enough to stretch or adjust our innate style to make the impression we want.

To understand how you resemble or differ from others, it helps to know the four dimensions of personality type. Everyone is born with -- and remains -- one of the 16 unique types for life. Each of us has an innate "preference" (much like being right- or left-handed) for how we operate in the world, even though our behavior may vary depending on the given situation. For example, people often act differently at the annual office holiday party than they do at a client presentation.

The first dimension of personality type is how people are energized and where they direct their energy (externally or internally). Extroverts are generally high-energy people who are energized by others and focus that energy in the outside world of people and things. Since extroverts find it easy to communicate verbally, they have a natural advantage in the interviewing process. However, because they "think out loud," they may inadvertently share more information than they, or the interviewer, would like.

Inward-looking introverts have a rich inner world of thoughts and ideas and often prefer to be by themselves. However, because they prefer to think before they speak, they are at a decided disadvantage in spontaneous discussions because they must respond quickly, an unnatural behavior to them. This is especially true in initial interviews, which tend to be brief.

The second dimension of personality type refers to how people gather information (either through their five senses or by making connections and using their "sixth sense"). Sensors are realistic and detail-oriented people who are attuned to the here and now. They have a penchant for facts, but may risk overloading interviewers with too many details, rather than emphasizing the results they have achieved.

Intuitives are usually imaginative, creative and future-oriented. But these "big-picture" people may not be specific enough, especially when dealing with a down-to-earth sensor interviewer. In fact, among U.S. residents, sensors outnumber intuitives by about 2 to 1. Therefore, it’s likely that your interviewer will be a sensor.

The third dimension of personality type -- thinking and feeling -- describes whether you base decisions primarily on objectivity and logic or are more persuaded by personal values and how your decision will affect others. Thinkers may be described as "tough minded," while feelers may be considered "tender hearted."

While thinkers pride themselves on their accomplishments, they often fail to make all-important personal connections, which can be disastrous, if, for example, your interviewer is a feeler. On the other hand, feelers are good at developing rapport (especially feelers who are also extroverts) but may not be assertive when selling themselves. And if their interviewer is a thinker, feelers may misinterpret his or her lack of warmth as rejection and become discouraged.

The fourth dimension of personality type describes how people prefer to organize their world and live their lives. Judgers are product-oriented people who seek closure and are driven to have things settled. Process-oriented people, known as perceivers, prefer to go with the flow and keep their options open.

As with the other three dimensions, both types have strengths and weaknesses when it comes to interviewing. Apt to make plans and be time conscious, judgers may not learn as much as they can about a company or interviewer in advance, nor ask important questions during the meeting. The more spontaneous perceivers may be unprepared or allow precious interview time to pass without making key points.

When all four preferences are combined, a powerful synergy occurs, which creates the 16 unique personality types, such as "ENFP" (Extrovert, Intuitive, Feeling, Perceiver) or "ISTJ" (Introvert, Sensor, Thinking, Judger). Can you begin to recognize your tendencies from these brief descriptions?

Now that you know more about the components of personality type, you may be ready to give "speed-reading" a try. In the following brief scenario, imagine you’re the candidate. Let’s see what you can quickly learn about the interviewer.

Your interviewer has a strong work ethic. She values responsibility and dedication to work above all else. She’s a serious, no-nonsense person. Her demeanor and appearance are formal and appropriately professional, and her office and desk are neat and uncluttered. She’s very conscious of time and quickly ends a meeting once business has been completed. These are all clues that she’s a judger (J).

It’s evident she’s a high-energy person because she did most of the talking, rarely pausing to think things through and speaking fairly rapidly. It’s quite easy to determine that she’s an action-loving extrovert (E).

Your interviewer was very specific and cited many details. She used simple, direct language. The only books in her office were reference guides and policy manuals. These clues, as well as the statistics on the greater prevalence of sensors, makes her likely to be a sensor (S).

Finally, you identified her as a thinker (T) because she chose to display impersonal certificates of achievements instead of more personal photographs of family, friends or pets. Her demeanor was businesslike and she did little to make you feel comfortable in a stressful situation. She didn’t smile much, nor did she compliment you on the achievements reflected in your resume.

You’re now fairly confident that she’s an Extrovert, Sensing, Thinking, Judging type or "ESTJ." How does your ability to "speed-read" her help you to convince her you’re the right candidate?

Because she’s an extrovert, you’ll want to show her that you’re also an action-oriented person, capable of thinking on your feet. Preparing answers to anticipated questions in advance (especially if you’re a naturally "think-before-you speak" introvert) should help you to respond more quickly than you naturally prefer. Since she’s a sensor, you’ll want to provide her with adequate details, facts and specifics. And you’ll want to quantify in concrete terms how your activities benefited your last employer. Because you’ve identified her as a thinker, you don’t expect a "warm, fuzzy" reception. You know she’ll make her decision based on an objective analysis of your competence, rather than whether she likes you as a person.

To succeed with this hiring manager, you must stress your achievements and accomplishments. Since you believe she’s a judger, you should approach the interview with the serious, no-nonsense, businesslike attitude she prefers. You must be prepared, succinct and respectful of her time constraints.

Trying to learn and respond to an interviewer’s personality type is common sense, says Marky Read, a principal of Career Networks & ProSearch of Burlington, Vt.

"There’s no denying the intangible but powerful ‘personal chemistry’ factor which occurs in many interviews," she says. "Candidates who can make the interviewer feel comfortable with them have a much greater chance of getting the job."

You aren’t guaranteed success just because you can speed-read interviewers. However, this technique can help you to get a foot in the door and a leg up in business -- and personal -- interactions. That’s why many people view this ability as the next best thing to having X-ray vision.

-- Mr. Tieger and Ms. Barron-Tieger are co-authors of "The Art of Speedreading People," "Do What You Are" and "Nurture by Nature," (all from Little, Brown and Co.). To participate in their research on a new book about personality type and relationships, visit www.personalitytype.com on the Internet.