Extraversion is made of six related tendencies: friendliness, gregariousness, assertiveness, activity level, excitement-seeking and cheerfulness. The 120-item Big Five test scores each with four items, so one extraversion percentile is the sum of six scores that can sit far apart.
The six facets
Friendliness is warmth and ease with other people: making friends easily and letting them close. Gregariousness is liking for crowds and company, the facet nearest to what sociable means in everyday speech. Assertiveness is taking charge and speaking up. Activity level is pace of life, keeping busy rather than taking it easy; it is about tempo, not people. Excitement-seeking is appetite for thrills and risk, and has the least to do with liking people. Cheerfulness is how readily joy and enthusiasm arise, and is the facet most tied to happiness. The names are those used by Johnson (2014), whose IPIP-NEO-120 measures thirty facets of the Big Five with four items each. In his sample of 619,150 people the extraversion facets had alphas from .69 for activity level to .85 for assertiveness.
Why the facets are worth reading
A domain score is an average, and an average hides. Ashton, Lee and Paunonen (2002) asked what the core of extraversion is and found social attention, the enjoyment of being noticed and engaged with, ran through the facets more consistently than sociability or reward did. Roberts, Walton and Viechtbauer (2006) found that the assertive side of extraversion rises through young adulthood while the sociable side changes little, so two facets of one trait follow different paths across the life course. Within one person the facets need not move together either: a quiet person can take charge in a crisis, and a sociable person can hate risk.
What a facet score does not mean
A facet is four items, so each facet score is coarser than the domain score and moves more between attempts; a facet a band away from the others is worth noticing, a few points is not. A low gregariousness score is not shyness, which is discomfort around people rather than a low appetite for them. A high assertiveness score is a readiness to lead, not a measure of how well a person leads. A high activity level says nothing about fitness; it describes how full a person likes their days.
What it means for your results
The strip shows where your overall extraversion sits among 410,376 people who took the same inventory. Under it the test lists the six facets, and the pattern tells you more than the total. Someone at the 50th percentile overall may be there because every facet is middling, or because high cheerfulness and friendliness balance low assertiveness and excitement-seeking, and those are different people.
The Big Five test takes about twelve minutes and scores all thirty facets. Each facet of extraversion has its own page explaining what a high and a low score look like.