What is meant by "personal impact and articulation skills" in the context of border entry?

Personal impact and articulation refer to a person’s physical appearance and behaviour when they present themselves to the immigration officer, and the way they answer questions. As noted by phoog’s response, immigration officers have a very short amount of time to determine whether a person complies with the immigration rules, and whether the person is credible with their responses.

This document, though a bit old, reports on a study on the immigration officers’ decision-making process during a landing interview. A person’s presentation at the immigration officer forms a key part in determining whether the person should be further questioned:

Officers might also take into account how passengers behaved at the desk; their dress, appearance and general demeanour were also seen as possible “clues” to their plausibility and, therefore, the need for questioning. (page v)

The section on “Passenger’s presentation of self” from page 15 provides some examples of behaviours which may trigger further questioning (i.e. poor personal impact and articulation skills):

• behaving in an unusual way (e.g. swapping queues to fall further back)
• agitation and nervousness
• uncertainty, evasiveness or lack of co-operation
• overconfidence (in an attempt to speed up the interview process or try to compensate for nervousness)
• appearing uncomfortable in their clothing, as though this is not their usual attire, for example:
  

  men in suits or shirts that are much too big, wearing ties with knots that suggest the passenger has never worn one before; men in suits but not
  wearing socks; and people in ill-fitting shoes

• physical appearance not consistent with their answers

However, there is an overall caveat:

Sometimes it is more of an overall impression that the [Immigration Officer] responds to, including how comfortable passengers seem, how they speak and communicate, how open they are, as well as how they are dressed. It is this combination of factors that leads an IO to accept or question whether the passenger is genuinely what they claim to be. Officers vary, however, in terms of how much store they place on the passengers’ behaviour and appearance. Some admit to forming a quick impression, which puts them on the alert. Other officers, however, were much more circumspect, claiming that appearances can be deceptive. People who look “very shabby” can turn out to be well educated professionals, such as university professors; men in the building trade may choose to dress up for travel because they wear jeans the rest of the time; passengers may dress particularly smartly because they are visiting relatives. [Chief Immigration Officers] in particular stressed the importance of not judging too much by appearances. Although an officer may form some impression of the socio-economic circumstances of a passenger, this may not be correct, so officers should concentrate on their questions rather than relying too much on the external impressions.

Personal impact refers to how a traveler presents him- or herself to an immigration officer. Some people may appear more credible, while others may seem less so. Some people may appear nervous, others confident. Some people may appear to be aggressive or demanding, while others may be cooperative.

The traveler’s appearance and demeanor have an impact on the officers who are judging whether to admit them to the country. In some respects, this may be unfortunate, because it invokes the specter of discrimination based on things like appearance. On the other hand, an immigration officer’s job is to judge people, mostly in a very short time, to determine whether they meet the criteria for admission. One way of judging people is on the basis of their personal impact, and a person’s credibility is certainly something they can and should question if they have a reason to do so.

Articulation denotes a person’s ability to express a position. In this case, articulation skills come into play when a traveler is asked to explain the purpose of his or her visit. The more coherent the explanation, the more likely it is to meet with success. Similarly, if an immigration officer misunderstands some evidence presented at the border, such as a bank statement, it will be necessary to articulate the nature of the misunderstanding.

For example, suppose a traveler brings her university diploma with her, and this is discovered during a search of her bags, leading an immigration officer to suspect that she has arrived to look for work. If she has an alternative explanation for bringing the diploma, she may satisfy the officer. The success of that explanation will depend in part on her articulation skills.