Course:PSYC305/2013ST2/ClassProject/3.2 Method - Measures

Measures

The measure utilized was a self-report questionnaire, which was administered online. The questionnaire also included each participant's scores of the Big Five Personality Traits based on the International Personality Item Pool (IPIP) Big Five Inventory. The Big Five Inventory is a self-report inventory designed to measure the Big Five dimensions, and it was given in the course material for participants to complete. The IPIP is a large public collection of items that are used in personality tests to measure differences between individuals. There are many variations of the IPIP. The type that was used in this study included the following five sub types: Surgency or Extraversion, Agreeableness, Conscientiousness, Emotional Stability and Intellect or Imagination. Each sub type was based on a 10 point scale (the smaller version) or a 20 point scale (the more detailed version), including both the positive extremes of the specific characteristic as well as the negative extremes. It is quite brief for a multidimensional personality inventory with 44 IPIP items in total, and consists of short phrases with relatively accessible vocabulary. The 44 items were administrated with a 5-point Likert scale ranging from 1 (disagree strongly ) to 5 (agree strongly).

Validity and Reliability of the Big Five Inventory

The internal consistency and concurrent validation of the IPIP Big-Five are now proven in the United States, Scotland, New Zealand, Croatia, and China (Zheng et al., 2008). This growing list shows the external validity and generalizability across cultures that the scale possesses.The Big Five Inventory components of the IPIP have been translated from English into many other languages though there is not much research comparing the results (Zheng et al., 2008). Zheng et al. (2008) conducted a study in which they found the IPIP Big-Five markers (except Agreeableness) to be highly correlated to the Chinese version, and therefore generalizable to a larger population.

Previous research has found the BFI to have considerable internal consistency reliability and test re-test reliability as it has been seen that through longitudinal studies, participants responded to the questions similarly. For example, even the concurrent validity was high since the cross-sectional changes that was based on different age groups was similar to previous research. The average level of Extraversion and Openness to Experience decreased with age, while Agreeableness, Conscientiousness and Emotional Stability increased. Even when tested within 3 different samples (consisting of the general population, students and the Lothian Birth Cohort of 1921 - i.e. those who had taken a part of Scottish Mental Survey), all 3 samples had roughly the same scores (Gow, Whiteman, Pattie & Deary, 2005).