TABLE 2.

Item wording and overview of the psychometric properties of the scales and items used in the study before (pretest) and after (posttest) teaching intervention

Scale	Itema	Item discriminatory powerb		αc
		Pretest	Posttest	Pretest	Posttest
Stigma: self-perception	(SEP1): If you met Mark, would you be willing to strike up a conversation with him?	0.373	0.549	0.77	0.86
	(SEP2): Would you attend a party where Mark was present?	0.675	0.753
	(SEP3): Would you attend a party where Mark was preparing dinner?	0.666	0.774
	(SEP4): Would you be willing to work in the same office with Mark?	0.583	0.742
Stigma: social perception	(SOP1): Most people would be happy to sit next to Mark on the bus.	0.386	0.436	0.61	0.68
	(SOP2*): Most people would try to avoid talking to Mark.	0.493	0.53
	(SOP3): Most people would be happy to eat something that Mark has cooked.	0.403	0.509
	(SOP4*): Most people would think Mark should be in hospital for a long time.	0.293	0.396
Disgust	(D1): When I am in my room and I see a bed bug, I become frightened.	0.287	0.408	0.52	0.63
	(D2*): I think working with real bed bugs in class would be exciting.	0.209	0.376
	(D3): If the teacher brought live bed bugs into class, I would prefer to leave the classroom.	0.304	0.471
	(D4*): Bed bugs are pretty animals.	0.262	0.288
	(D5): Bed bugs are disgusting.	0.392	0.397
Psychological distance	(PD S1): Bed bugs mainly affect people who live differently than I do.	0.414	0.527	0.63	0.65
	(PD R1): I first associate bed bugs with other countries.	0.334	0.5
	(PD R3): Bed bugs are mainly found in places that are far away from here.	0.581	0.383

^aThe fictitious person Mark was stated to suffer from a bed bug infestation. An asterisk (*) indicates an item was reverse coded.

^br_it, item discriminatory power.

^cα, Cronbach’s alpha.