Final answer:
Personality inventories, such as the MMPI and MBTI, would most likely be used to measure the Big 5 personality factors.
Step-by-step explanation:
The "Big 5" would most likely be measured via a(n) personality inventory. Personality inventories, such as the Minnesota Multiphasic Personality Inventory (MMPI) and the Myers-Briggs Type Indicator (MBTI), use a series of questions or statements to assess an individual's personality traits. These inventories provide a self-report of an individual's personality characteristics and are commonly used to measure the Big Five personality factors: openness to experience, conscientiousness, extroversion, agreeableness, and neuroticism.