Table 3.

Descriptive statistics of the choice certainty level. Non-representative sample of 1458 adolescents in France, January–March 2020.

	Number of choice observations	Mean	Standard Deviation	Q2 (Q1-Q3)	% with constant certainty	% with low mean certainty (0–5)	% with high mean certainty (9–10)
Overall (n = 1458)	14575	7.6	2.2	8 (6–10)	8.1	7.1	21.2
Non-uniform sample (n = 711)	7105	7.2	2.3	8 (6–9)	2.7	8.3	10.7
Uniform sample (n = 747)	7470	8.0*	2.0	8 (7–10)	13.3*	6.0	31.2*
Serial demanders (n = 659)	6590	8.0*	1.9	8 (7–10)	9.1*	4.0*	30.2*
Serial non-demanders (n = 88)	880	7.5*	2.7	8 (5–10)	44.3*	21.6*	38.6*

Notes: n: number of respondents; Q1 = first quartile, Q2 = second quartile, Q3 = third quartile.* P-value test vs non-uniform <0.01. Respondents, including those with unvaried certainty, can have low (0–5), medium (6–8) or high (9–10) mean certainty.