The Big Five

Paul Costa and Robert McCrae developed the theory of the Big Five personality traits. They used the lexical approach which says that the most important features of personality are found in language, to find the Big Five Traits. They define the Big Fives as openness to experience, conscientiousness, extroversion, agreeableness, and neuroticism. The theory says that all people fit in at some point on a scale for each trait. For instance extroversion some people will be very extroverted, while other won't much extroversion at all, but they still have a little bit of extroversion in their personality. The Big Five has been used to predict job performance those with high agreeableness and low neuroticism are associated with good job performance.
The Big Five personality assessment remains relatively stable over time, allowing researcher to compare results across generations, as well as across cultures. The stability of the results lets researchers look at the heritability of personality over time as well.
The Big Five is an important theory as it allows us to look at all personality equally. Since inventory can be used universally we can compare results across the world, the nation, the state, etc.. Comparisons allow us to see similarities in personalities that can explain what type of personality creates a leader, which personality type makes a good worker, among other explanations.
I took a personality test based off the Big Five theory and it provided a lot of good insight to me about who I am as a person as well as my compatibility with others. The test told me how I should deal with people with different personalities as well as how they should deal with me. The information that the results put how I see the world into words, that I could not of come up with myself. I thought that was the best part of taking the test.