The abstract images used in the Projective Differential are grouped into different sets, called stimulus sets. There are several different sets of images available for use in PD administrations, and two basic kinds of sets–there are several JOG sets and one RESEARCH set. The set chosen for any given administration depends upon the context, as each set has different particular strengths.
JOG Stimulus sets (J10 or J30):There are four versions of the J10, each of which is composed of 10 pairings that consist of all possible pairings of five abstract images. The pairs are sequenced such that no picture appears in successive pairings and each picture appears an equal number of times in left hand and in right hand positions. The four versions are:
- Classic – The first of the current JOG sets to be developed, the Classic J10 is also the most used. It is rich in terms of generating a variety of associations to epitomizing (and antithetical) pictures, and is good at producing valid quantitative scores.
- Evaluative – The Evaluative J10 set consists of the pictures that most clearly distinguish between connotative opposites such as “good vs. bad,” “strong vs. weak,” etc. thus making possible the calculation of the most valid quantitative scores among all the JOG sets.
- Evocative – The Evocative J10 set was chosen on the basis of its ability to tap into evocative connotative space, i.e., in research the images proved to be rich in terms of the responses to “what do the images make you think of?” and “how do they make you feel?”, while also doing a very good job of producing quantitative connotative scores.
- Open-Source – The newest version of the JOG. This set was recently developed in order to provide a freely available, online version for individual use as a “head-gut check.” It has not undergone the research and testing of the earlier versions, and as such less is known about its particular strengths in comparison with the other versions.