The Zimbardo time perspective inventory: Time for a new strategy, not more new shortened versions

Researchers continue to attempt to resolve the psychometric problems associated with the five-factor Zimbardo Time Perspective Inventory through the development of shortened forms of the scale. These atheoretical efforts have been data driven and have resulted in scales whose reliability and validity have not been subsequently supported. The purpose of this paper was to explore the factorial validity and reliability of new short scales on samples independent from which they were developed. We used data from five different samples in four different countries (Australia, Britain, Slovenia, and the United States) to examine the psychometric validity and reliability of three recently developed scales, the ZTPI-20, ZTPI-17, and ZTPI-15. Results regarding validity were equivocal for all scales and reliability coefficients were suboptimal in all samples. We conclude by stressing the necessity for a theoretically driven approach to enhancing the psychometric assessment of time perspective rather than simply sacrificing reliability or discriminant validity for improved model fit in a shorter scale.