IMC 2006 statistics — difficulty & discrimination

Studolymp / IMC / 2006

IMC 2006

contestants

241

problems

12 (6+6)

score scale

0–20

per-problem results

yes

Notes on this edition’s data

Scored on a 20-point scale this era (8/16 = solved).

Per-problem difficulty

Day 1

Day 2

Difficulty vs discrimination

Each dot is one problem. X — how many solved it (scored ≥ 8 of 10); Y — discrimination, i.e. how well the problem told strong contestants from weak ones (score-vs-total correlation).

A good problem sits high and away from the edges. Bottom-left dots separated nobody — almost everyone failed them the same way.

Problem statistics

Same data as the Day 1 / Day 2 charts above.

	#	difficulty	avg	solved	near-0	disc	topics
Day 1
	P1	easy	9.2	88%	1%	0.39	real analysis
	P2	easy	7.1	54%	18%	0.51	number theory
	P3	hard	2.5	16%	64%	0.39	linear algebra number theory
	P4	very hard	1.7	9%	69%	0.42	polynomials
	P5	very hard	1.4	11%	80%	0.31	inequalities real analysis
	P6	killer	0.3	1%	95%	0.18	real analysis polynomials
Day 2
	P7	easy	9.2	88%	3%	0.35	combinatorics geometry
	P8	easy	8.2	76%	4%	0.41	real analysis functional equations
	P9	very hard	1.3	6%	68%	0.20	real analysis inequalities
	P10	medium	3.6	31%	53%	0.55	linear algebra
	P11	medium	3.8	35%	55%	0.53	number theory polynomials
	P12	killer	0.0	0%	99%	0.16	linear algebra

Field cohort = total ≥ 6 points; difficulty is computed live by the API. Discrimination is the corrected item–total correlation.