Trivia Pilot (knowledge & curiosity)
This report summarises pilot data collected to test participants’ knowledge and curiosity ratings of our assembled trivia database (N=387).
As of 2018-10-15, we received pilot ratings from 11 pilot participants.
Knowledge
In phase I, Gruber asked participants to rate their knowledge of presented trivia items on a 1-6 scale. In phase II, Gruber did not present participants in-scanner with trivia items for which they indicated they knew they answer (response of 6; black). However, all ratings that indicated any uncertainty (responses of 1-5; greys) were presented in-scanner.
On average, our pilot participants indicated they knew the answer to 9.97% of our trivia dataset (range 3.09% to 19.19%). Gruber does not report the complementary figure. However, assuming that future study participants will understand knowledge in the same way our pilot participants have, it seems likely that our study participants will indicate similar or lower levels of knowledge (due to high education of pilot participants).
Curiosity
Note: As per Gruber, trivia items that a participant indicated as ‘known’ have been removed from the curiosity rating analysis.
For optimum efficiency of phase I administration, we want an equal number of items to be rated low curiosity (response of 1-3; reds) vs. high curiosity (response of 4-6; greens). Across all pilot participants, 40.88% of items were rated as low curiosity, and 59.12% of items were rated as high curiosity. This pattern also holds at the individual level, and is generally consistent with Gruber’s finding that, on average, participants gave low curiosity ratings on 58 items (range 56-58), and high rating on 85 items (range 56-173). This gives us good reason to think that an estimated dataset size of N=310 items (387 - liberal 20% known = 310) should be more than sufficient to identify the required N = 56 per curiosity condition. We should, however, ensure that MDD pilots have comparable curiosity ratings as HC pilots.