Goldberg's International Personality Item Pool (IPIP) big-five personality factor markers currently lack validating evidence. The structure of the 50-item IPIP was examined in two different adult samples (total N=811), in each case justifying a 5-factor solution, with only minor discrepancies. Age differences were comparable to previous findings using other inventories. One sample (N=193) also completed additionally another personality measure (the TIPI Short Form). Conscientiousness, extraversion and emotional stability/neuroticism scales of the IPIP were highly correlated with those of the TIPI (r=0.62 to 0.65, P=0.01). Agreeableness and Intellect/Openness scales correlated less strongly (r=0.54 and 0.58 respectively, P=0.01). The IPIP scales have good internal consistency (a=0.88) and relate strongly to major dimensions of personality assessed by the two questionnaires.
Keywords: IPIP Big-Five factor markers; Personality; validation.