Table 2.

Easiness (ε) and discrimination (δ) parameters for the 23 items of the Extraversion scale.

New form	Original form	Item n.	Text	ε	δ
	✓	47	Are you mostly quiet when you are with other people?	−5.623	−0.395
✓	✓	20	Do you enjoy meeting new people?	−1.914	1.613
	✓	11	Are you rather lively?	−1.605	1.311
✓	✓	58	Do you like mixing with people?	−1.592	2.182
		33	Do you prefer reading to meeting people?	−1.246	0.973
	✓	94	Do other people think of you as being very lively	−1.180	0.805
✓		28	Do you like going out a lot?	−1.105	1.193
		72	Do you often take on more activities than you have time for?	−0.832	0.570
		69	Do you often make decisions on the spur of the moment?	−0.755	0.489
		36	Do you have many friends?	−0.652	1.525
✓	✓	78	Can you get a party going?	−0.636	1.418
✓		67	Do you like doing things in which you have to act quickly?	−0.608	0.783
✓	✓	16	Can you usually let yourself go and enjoy yourself at a lively party?	−0.536	1.676
✓	✓	6	Are you a talkative person?	−0.468	1.211
		55	Do you like telling jokes and funny stories to your friends?	−0.365	0.705
		63	Do you nearly always have a ‘ready answer’ when people talk to you?	−0.230	0.401
✓	✓	45	Do you usually take the initiative in making new friends?	−0.171	1.741
✓	✓	24	Do you tend to keep in the background on social occasions?	0.151	1.658
✓	✓	51	Can you easily get some life into a rather dull party?	0.402	1.729
		40	Would you call yourself happy-go-lucky?	0.753	0.944
✓		61	Have people said that you sometimes act too rashly?	0.934	0.582
		1	Do you have many different hobbies?	0.974	0.519
✓	✓	90	Do you like plenty of bustle and excitement around you?	1.648	0.884

The items are ordered by increasing easiness. The items included in the new and in the original short forms are marked by “✓.”