All respondents answered a questionnaire consisting of standard demographic questions followed by items from the complete DPS, GPS, AIP, and IPS scales. The DPS (Mann, 1982, unpublished; Mann et al., 1997 (
link)) contains five items that primarily focuses on delay in planning and decision making, e.g., “I waste a lot of time on trivial matters before getting to the final decisions,” though has one item related to implementation, “Even after I make a decision I delay acting upon it” (DPS 2). Internal reliability for the DPS is relatively high, α = 0.70–0.83 (Mariani and Ferrari, 2012 (
link)). The GPS (Lay, 1986 (
link)) encompasses 20 items focusing primarily on implemental delay, e.g., “Even jobs that require little else except sitting down and doing them, I find that they seldom get done for days” (GPS 7). Two versions of the GPS exist, a general version and a version adapted for students specifically. The general version was used here. It has a good internal consistency, α = 0.86 (Lay, 1986 (
link)). The AIP (McCown et al., 1989 (
link)) contains a mix of items addressing decisional and implemental delay, as well as lateness (see
Table 2). Test-retest reliability of this scale is relatively high,
r = 0.71, as is internal consistency, α = 0.86 (Ferrari et al., 2005 ). The IPS (Steel, 2010 (
link)) is a nine-item scale focusing on implemental delay, e.g., “I delay tasks beyond what is reasonable” (IPS 7). The IPS demonstrates good internal reliability, α = 0.91 (Steel, 2010 (
link)). Of note, the PPS was not included as a separate scale, as this scale is composed of 12 items from the DPS, GPS, and AIP. Steel (2010) (
link) reported internal consistency of the PPS at α = 0.92. For discriminant validity purposes, respondents answered the five-item Satisfaction with Life Scale (SWLS; Diener et al., 1985 (
link)). All items were answered on a common 1–5 scale, 1 = “Very seldom or not true of me,” 5 = “Very often true, or true with me.” All answered a total of 159 items. First, respondents answered the demographic questions, then the procrastination scales of the present study and finally the SWLS. Items were presented in fixed order, one scale at a time.
Svartdal F, & Steel P. (2017). Irrational Delay Revisited: Examining Five Procrastination Scales in a Global Sample. Frontiers in Psychology, 8, 1927.