Booklets and items

We have a total of 8 booklets The number of items in each booklet is: 73, 73, 73, 73, 73, 73, 73, 73. The number of students completing each boklet is: 318, 245, 306, 240, 230, 169, 150, 185. A total number of 1843 students participated in this pilot-study, responding to a total of 423 items.

The the number of observations per item:
item1 observation1 item2 observation2 item3 observation3
Kopi.av.ord_166_.rope1 318 ord_199_.natt500 546 ord_427_.våren500 245
Kopi.av.ord_290_.skolen1 318 ord_200_.natt200 468 ord_428_.våren200 306
ord_001_.dag2 318 ord_201_.uret2 169 ord_430_.dukken1 185
ord_003_.dag500 456 ord_202_.uret1 150 ord_431_.dukken500 169
ord_005_.tak2 318 ord_203_.uret500 240 ord_432_.dukken200 245
ord_006_.tak1 185 ord_204_.uret200 318 ord_435_.sukker500 150
ord_007_.tak500 169 ord_206_.leke1 318 ord_436_.sukker200 503
ord_010_.sak1 230 ord_207_.leke500 430 ord_442_.luktet1 306
ord_011_.sak500 169 ord_208_.leke200 240 ord_443_.luktet500 185
ord_012_.sak200 318 ord_210_.høne1 240 ord_444_.luktet200 245
ord_013.lam2 318 ord_211_.høne500 395 ord_451_.dusten500 306
ord_014.lam1 150 ord_212_.høne200 503 ord_452_.dusten200 319
ord_015.lam500 240 ord_213_.tann2 230 ord_455_.skøyter500 185
ord_018_.rar1 230 ord_215_.tann500 245 ord_456_.skøyter200 319
ord_019_.rar500 475 ord_216_.tann200 318 ord_458_.tenker1 306
ord_020_.rar200 318 ord_217_.lang2 240 ord_459_.tenker500 150
ord_021_.far2 245 ord_218_.lang1 185 ord_460_.tenker200 185
ord_022_.far1 169 ord_219_.lang500 319 ord_462_.krangle1 318
ord_023_.far500 185 ord_220_.lang200 475 ord_464_.krangle200 230
ord_025_.lat2 245 ord_221_.bart2 245 ord_467_.trasket500 563
ord_027_.lat500 306 ord_223_.bart500 491 ord_468_.trasket200 230
ord_028_.lat200 150 ord_224_.bart200 399 ord_470_.vinduer1 318
ord_029_.hav2 245 ord_226_.bråk1 306 ord_471_.vinduer500 150
ord_031_.hav500 354 ord_227_.bråk500 230 ord_472_.vinduer200 546
ord_034_lek1 245 ord_228_.bråk200 319 ord_475_.steiker500 169
ord_035_lek500 150 ord_230_.brød1 245 ord_476_.steiker200 546
ord_038_mel1 318 ord_231_.brød500 425 ord_478_.marsjerer1 230
ord_039_.mel500 240 ord_232_.brød200 306 ord_479_.marsjerer500 713
ord_042_.pen1 318 ord_233_.hest2 306 ord_482_.kantarell1 230
ord_043_.pen500 230 ord_234_.hest1 230 ord_483_.kantarell500 185
ord_044_.pen200 185 ord_235_.hest500 318 ord_484_.kantarell200 563
ord_046_.fem1 245 ord_236_.hest200 150 ord_486_.tallerken1 240
ord_047_.fem500 169 ord_239_.såpe500 1843 ord_487_.tallerken500 185
ord_049_.ser2 230 ord_241_.bord2 230 ord_488_.tallerken200 399
ord_050_.ser1 169 ord_242_.bord1 150 ord_491_.skrutrekker500 169
ord_051_.ser500 395 ord_243_.bord500 169 ord_492_.skrutrekker200 470
ord_053_.les2 185 ord_244_.bord200 245 ord_494_.glitret1 240
ord_054_.les1 240 ord_246_.rote1 306 ord_495_.glitret500 185
ord_055_.les500 245 ord_247_.rote500 380 ord_496_.glitret200 318
ord_057_.fat2 230 ord_248_.rote200 551 ord_499_.praktisk500 399
ord_059_.fat500 318 ord_249_.trær2 185 ord_500_.praktisk200 653
ord_060_.fat200 245 ord_251_.trær500 240 ord_503_.speilet500 565
ord_061_.fin2 306 ord_252_.trær200 395 ord_504_.speilet200 558
ord_063_.fin500 240 ord_254_.klam1 306 ord_506_.planter1 245
ord_065_.rir2 150 ord_255_.klam500 487 ord_507_.planter500 185
ord_066_.rir1 240 ord_256_.klam200 240 ord_508_.planter200 306
ord_067_.rir500 230 ord_257_.fyre2 306 ord_511_.kontanter500 503
ord_068_.rir200 245 ord_258_.fyre1 185 ord_512_.kontanter200 240
ord_069_.ris2 306 ord_259_.fyre500 318 ord_516_.kanonen200 624
ord_071_.ris500 240 ord_260_.fyre200 169 ord_519_.fantastisk500 150
ord_072_.ris200 185 ord_262_.slått1 240 ord_520_.fantastisk200 306
ord_073_.lov2 185 ord_263_.slått500 399 ord_523_.transport500 169
ord_074_.lov1 306 ord_266_.frosk1 318 ord_524_.transport200 306
ord_075_.lov500 245 ord_267_.frosk500 470 ord_528_.morderne200 653
ord_077_.bil2 306 ord_268_.frosk200 185 ord_530_.prestene1 185
ord_079_.bil500 415 ord_271_.sykle500 563 ord_531_.prestene500 865
ord_080_.bil200 240 ord_272_.sykle200 230 ord_532_.prestene200 245
ord_082_.kos1 306 ord_274_.lekser1 169 ord_534_.presentere1 169
ord_083_.kos500 230 ord_275_.lekser500 563 ord_535_.presentere500 185
ord_085_.rop2 169 ord_278_.klokke1 306 ord_536_.presentere200 318
ord_087_.rop500 306 ord_279_.klokke500 503 ord_538_.instrument1 169
ord_088_.rop200 150 ord_280_.klokke200 230 ord_539_.instrument500 185
ord_090_.hun1 150 ord_282_.synge1 169 ord_540_.instrument200 318
ord_091_.hun500 306 ord_283_.synge500 240 ord_542_.balansere1 185
ord_092_.hun200 169 ord_284_.synge200 563 ord_544_.balansere200 318
ord_093_.bur2 169 ord_287_.arver500 1843 ord_547_.direkte500 318
ord_095_.bur500 335 ord_290_.skolen1 1525 ord_548_.direkte200 470
ord_096_.bur200 306 ord_295_.hunden500 319 ord_551_.ekspertene500 318
ord_097_.dyr2 230 ord_296_.hunden200 470 ord_552_.ekspertene200 230
ord_098_.dyr1 185 ord_299_.padle500 318 ord_554_.annerledes1 245
ord_099_.dyr500 240 ord_300_.padle200 335 ord_555_.annerledes500 169
ord_103_.sør500 415 ord_302_.esker1 318 ord_556_.annerledes200 306
ord_104_.sør200 306 ord_303_.esker500 546 ord_559_.stativene500 240
ord_105_.dør2 185 ord_304_.esker200 399 ord_560_.stativene200 399
ord_107_.dør500 245 ord_307_.planke500 503 ord_564_.stranden200 558
ord_108_.dør200 240 ord_308_.planke200 319 ord_567_.skjelett500 245
ord_109_.søl2 150 ord_310_.niste1 240 ord_568_.skjelett200 306
ord_111_.søl500 318 ord_311_.niste500 399 ord_570_.strutsene1 306
ord_113_.bål2 169 ord_312_.niste200 563 ord_571_.strutsene500 150
ord_115_.bål500 150 ord_316_.bamse200 1843 ord_572_.strutsene200 245
ord_116_.bål200 230 ord_318_.hjerne1 245 ord_575_.spraglete500 240
ord_117_.bra2 240 ord_319_.hjerne500 230 ord_576_.spraglete200 456
ord_119_.bra500 245 ord_320_.hjerne200 546 ord_579_.uhøflig500 551
ord_120_.bra200 169 ord_323_.lappen500 240 ord_580_.uhøflig200 230
ord_121_.arm2 150 ord_324_.lappen200 414 ord_583_.hemmelig500 318
ord_123_.arm500 318 ord_327_.spruter500 470 ord_584_.hemmelig200 169
ord_124_.arm200 230 ord_328_.spruter200 306 ord_588_.slåsskamp200 1843
ord_125_.sol2 1843 ord_330_.bukser1 245 ord_591_.eksplosjon500 245
ord_129_.mus2 240 ord_331_.bukser500 335 ord_592_.eksplosjon200 240
ord_131_.mus500 318 ord_332_.bukser200 546 ord_595_.reparasjon500 169
ord_133_.bok2 1843 ord_335_.genser500 319 ord_596_.reparasjon200 551
ord_137_.syn2 240 ord_336_.genser200 470 ord_599_.pasning500 318
ord_139_.syn500 318 ord_338_.bakke1 150 ord_600_.pasning200 306
ord_141_.dele2 318 ord_339_.bakke500 318 ord_604_.sjenerte200 230
ord_143_.dele500 625 ord_340_.bakke200 240 ord_606_.ordentlig1 306
ord_144_.dele200 185 ord_342_.hjelm1 240 ord_607_.ordentlig500 245
ord_145_.lege2 169 ord_343_.hjelm500 318 ord_608_.ordentlig200 169
ord_146_.lege1 240 ord_344_.hjelm200 150 ord_611_.konsentrasjon500 306
ord_147_.lege500 491 ord_347_.bilde500 551 ord_612_.konsentrasjon200 150
ord_148_.lege200 563 ord_348_.bilde200 399 ord_615_.karakterer500 230
ord_150_.gate1 318 ord_351_.glade500 245 ord_616_.karakterer200 240
ord_151_..gate500 470 ord_352_.glade200 470 ord_619_.kjekler500 240
ord_152_.gate200 169 ord_354_.kosten1 318 ord_620_.kjekler200 245
ord_153_.hale2 240 ord_355_.kosten500 546 ord_623_.kraftverk500 306
ord_154_.hale1 185 ord_356_.kosten200 150 ord_624_.kraftverk200 169
ord_155_.hale500 563 ord_359_.visper500 230 ord_626_.overraskelsen1 150
ord_156_.hale200 230 ord_360_.visper200 240 ord_627_.overraskelsen500 185
ord_157_.møte2 245 ord_362_.kornet1 230 ord_628_overraskelsen200 245
ord_158_.møte1 169 ord_363_.kornet500 169 ord_631_.kraftanstrengelse500 230
ord_159_.møte500 456 ord_366_.silke1 169 ord_632_.kraftanstrengelse200 150
ord_160_.møte200 230 ord_367_.silke500 335 ord_635_.kalenderne500 306
ord_162_.nyse1 245 ord_368_.silke200 563 ord_636_.kalenderne200 150
ord_163_.nyse500 354 ord_371_.slave500 551 ord_639_.systemene500 245
ord_164_.nyse200 470 ord_372_.slave200 319 ord_640_.systemene200 169
ord_166_.rope1 1525 ord_375_.teller500 245 ord_643_.kikkertene500 240
ord_169_.våte2 150 ord_376_.teller200 335 ord_644_.kikkertene200 185
ord_170_.våte1 245 ord_378_.brøler1 150 ord_646_.landstedene1 150
ord_171_.våte500 470 ord_379_.brøler500 169 ord_647_.landstedene500 185
ord_172_.våte200 169 ord_380_.brøler200 503 ord_648_.landstedene200 240
ord_174_.kino1 230 ord_383_.gnager500 185 ord_651_.skyskraperen500 230
ord_175_.kino500 468 ord_384_.gnager200 306 ord_652_.skyskraperen200 245
ord_176_.kino200 185 ord_387_.eksem500 230 ord_655_.tørklær500 245
ord_177_.hjul2 185 ord_388_.eksem200 551 ord_656_.tørklær200 319
ord_178_.hjul1 240 ord_390_.kloden1 245 ord_659_.forklærne500 150
ord_179_.hjul500 720 ord_391_.kloden500 185 ord_660_.forklærne200 245
ord_180_.hjul200 150 ord_392_.kloden200 546 ord_663_.ferdighet500 470
ord_181_.peis2 318 ord_394_.flaske1 150 ord_664_.ferdighet200 169
ord_182_.peis1 150 ord_395_.flaske500 306 ord_667_.bagatellisere500 306
ord_183_.peis500 230 ord_396_.flaske200 399 ord_668_.bagatellisere200 169
ord_184_.peis200 546 ord_399_.styrke500 150 ord_671_.kvalmende500 240
ord_186_.sand1 169 ord_400_.styrke200 551 ord_672_.kvalmende200 245
ord_187_.sand500 503 ord_406_.skrape1 230 ord_692_.alarmanlegg200 185
ord_188_.sand200 306 ord_408_.skrape200 169 ord_699_.avslappende500 185
ord_190_.våge1 169 ord_411_.salve500 240 ord_700_..avslappende200 230
ord_191_.våge500 245 ord_412_.salve200 335 ord_708_.kontraktene200 150
ord_192_.våge200 240 ord_414_.lykten1 185 ord_712_.forvekslinger200 150
ord_193_.kort2 150 ord_416_.lykten200 318 ord_723_.legetimene500 230
ord_193_.kort200 306 ord_420_.mynter200 503 ord_744_.allsidighet200 185
ord_194_.kort1 318 ord_422_.drops1 230 ord_748_.fyrstikkeske200 185
ord_195_.kort500 230 ord_423_.drops500 185 ord_750_.skylde1 185
ord_198_.natt1 230 ord_424_.drops200 318 ord_750_.skylde500 306

Level of difficulty for the dichotomous items

We have 423 dichotomous items, and 0 polytomous items. Here is the the distribution of percentage correct for the dichotomous items:

The items were never answered incorrectly, and are removed from further analysis.

IRT modeling

Dichotomous items may be estimated with 2PL, while polytomous items may be fitted with the graded response model. The resulting test information curve is as follows:

Dichotomous items

Item parameters a (discrimination) and d (difficulty)
a d
Kopi.av.ord_166_.rope1 1.8 -2.5
Kopi.av.ord_290_.skolen1 1.0 -1.7
ord_001_.dag2 2.2 -1.6
ord_003_.dag500 2.1 -1.2
ord_005_.tak2 2.2 -2.5
ord_006_.tak1 1.8 -2.7
ord_007_.tak500 1.8 -2.7
ord_010_.sak1 -0.1 24.3
ord_011_.sak500 1.5 -2.7
ord_012_.sak200 1.1 -2.8
ord_013.lam2 1.7 -2.6
ord_014.lam1 1.1 -3.8
ord_015.lam500 2.0 -1.8
ord_018_.rar1 1.0 -3.9
ord_019_.rar500 1.5 -2.2
ord_020_.rar200 1.8 -1.4
ord_021_.far2 1.4 -3.1
ord_022_.far1 2.0 -2.6
ord_023_.far500 2.3 -2.2
ord_025_.lat2 0.9 -3.6
ord_027_.lat500 1.1 -2.3
ord_028_.lat200 0.7 -2.0
ord_029_.hav2 2.0 -2.2
ord_031_.hav500 2.3 -1.8
ord_034_lek1 1.2 -3.3
ord_035_lek500 1.2 -2.8
ord_038_mel1 1.3 -3.1
ord_039_.mel500 1.1 -3.0
ord_042_.pen1 1.7 -2.4
ord_043_.pen500 2.1 -2.3
ord_044_.pen200 1.2 -2.1
ord_046_.fem1 0.7 -3.4
ord_047_.fem500 1.1 -2.5
ord_049_.ser2 -0.3 13.4
ord_050_.ser1 0.9 -4.2
ord_051_.ser500 1.3 -2.6
ord_053_.les2 1.8 -3.4
ord_054_.les1 0.7 -5.1
ord_055_.les500 2.0 -2.3
ord_057_.fat2 1.9 -1.9
ord_059_.fat500 1.2 -2.4
ord_060_.fat200 1.6 -1.5
ord_061_.fin2 0.6 -5.9
ord_063_.fin500 1.5 -2.5
ord_065_.rir2 0.5 -8.4
ord_066_.rir1 0.4 -7.7
ord_067_.rir500 1.2 -3.2
ord_068_.rir200 1.3 -2.1
ord_069_.ris2 0.4 -10.4
ord_071_.ris500 1.1 -3.5
ord_072_.ris200 1.4 -2.4
ord_073_.lov2 1.2 -3.8
ord_074_.lov1 0.9 -4.7
ord_075_.lov500 1.0 -3.6
ord_077_.bil2 0.7 -3.0
ord_079_.bil500 1.0 -1.3
ord_080_.bil200 0.8 -0.8
ord_082_.kos1 1.7 -2.7
ord_083_.kos500 1.4 -2.8
ord_085_.rop2 4.1 -2.6
ord_087_.rop500 1.8 -2.3
ord_088_.rop200 2.7 -1.6
ord_090_.hun1 0.8 -3.8
ord_091_.hun500 1.2 -2.2
ord_092_.hun200 1.3 -2.2
ord_093_.bur2 1.2 -1.8
ord_095_.bur500 2.0 -1.3
ord_096_.bur200 2.8 -0.8
ord_097_.dyr2 1.3 -3.3
ord_098_.dyr1 3.1 -1.9
ord_099_.dyr500 1.2 -2.8
ord_103_.sør500 1.0 -3.4
ord_104_.sør200 0.9 -2.5
ord_105_.dør2 1.6 -1.8
ord_107_.dør500 1.6 -2.0
ord_108_.dør200 1.1 -2.4
ord_109_.søl2 0.4 -8.5
ord_111_.søl500 2.2 -1.9
ord_113_.bål2 1.1 -2.6
ord_115_.bål500 1.7 -1.5
ord_116_.bål200 2.0 -0.9
ord_117_.bra2 1.1 -2.8
ord_119_.bra500 2.0 -1.6
ord_120_.bra200 1.9 -1.5
ord_121_.arm2 1.4 -3.4
ord_123_.arm500 1.3 -2.6
ord_124_.arm200 1.4 -2.1
ord_125_.sol2 0.5 -8.6
ord_129_.mus2 1.2 -3.9
ord_131_.mus500 2.7 -1.8
ord_133_.bok2 1.5 -3.5
ord_137_.syn2 1.8 -2.4
ord_139_.syn500 1.7 -2.6
ord_141_.dele2 2.1 -1.9
ord_143_.dele500 2.2 -1.3
ord_144_.dele200 2.1 -1.0
ord_145_.lege2 2.9 -2.6
ord_146_.lege1 1.2 -2.5
ord_147_.lege500 1.8 -1.6
ord_148_.lege200 1.8 -1.1
ord_150_.gate1 1.4 -3.0
ord_151_..gate500 1.3 -2.6
ord_152_.gate200 1.3 -1.9
ord_153_.hale2 1.8 -2.1
ord_154_.hale1 0.9 -3.0
ord_155_.hale500 1.4 -2.0
ord_156_.hale200 1.5 -1.7
ord_157_.møte2 1.5 -2.3
ord_158_.møte1 0.5 -3.8
ord_159_.møte500 1.3 -1.9
ord_160_.møte200 1.6 -1.1
ord_162_.nyse1 2.1 -1.8
ord_163_.nyse500 2.3 -1.3
ord_164_.nyse200 2.6 -0.9
ord_166_.rope1 1.1 -3.2
ord_169_.våte2 1.3 -3.1
ord_170_.våte1 1.3 -2.5
ord_171_.våte500 2.0 -1.7
ord_172_.våte200 1.5 -1.6
ord_174_.kino1 1.9 -2.0
ord_175_.kino500 3.0 -1.3
ord_176_.kino200 2.4 -1.1
ord_177_.hjul2 0.5 -6.9
ord_178_.hjul1 1.1 -3.4
ord_179_.hjul500 1.3 -2.2
ord_180_.hjul200 2.0 -1.4
ord_181_.peis2 2.0 -2.0
ord_182_.peis1 1.9 -2.0
ord_183_.peis500 2.2 -2.0
ord_184_.peis200 2.2 -1.4
ord_186_.sand1 1.7 -1.7
ord_187_.sand500 2.1 -1.6
ord_188_.sand200 1.8 -1.4
ord_190_.våge1 1.7 -1.9
ord_191_.våge500 2.0 -1.1
ord_192_.våge200 2.6 -0.5
ord_193_.kort2 1.5 -2.9
ord_193_.kort200 1.8 -1.2
ord_194_.kort1 2.9 -1.6
ord_195_.kort500 1.4 -2.3
ord_198_.natt1 2.1 -2.6
ord_199_.natt500 1.4 -2.6
ord_200_.natt200 1.3 -2.5
ord_201_.uret2 0.9 -2.7
ord_202_.uret1 1.2 -2.3
ord_203_.uret500 0.7 -1.9
ord_204_.uret200 0.5 -1.7
ord_206_.leke1 2.6 -1.8
ord_207_.leke500 2.0 -1.7
ord_208_.leke200 1.9 -1.1
ord_210_.høne1 1.6 -2.2
ord_211_.høne500 2.1 -1.4
ord_212_.høne200 2.3 -1.0
ord_213_.tann2 0.9 -4.9
ord_215_.tann500 2.3 -1.9
ord_216_.tann200 1.5 -2.1
ord_217_.lang2 1.6 -2.6
ord_218_.lang1 1.1 -2.8
ord_219_.lang500 2.0 -1.7
ord_220_.lang200 1.4 -1.4
ord_221_.bart2 1.8 -1.7
ord_223_.bart500 2.1 -1.0
ord_224_.bart200 2.4 -0.5
ord_226_.bråk1 1.4 -2.3
ord_227_.bråk500 2.1 -1.4
ord_228_.bråk200 1.5 -1.1
ord_230_.brød1 4.0 -1.8
ord_231_.brød500 1.5 -2.5
ord_232_.brød200 2.0 -1.7
ord_233_.hest2 1.4 -2.6
ord_234_.hest1 1.9 -2.0
ord_235_.hest500 2.0 -2.0
ord_236_.hest200 2.2 -2.0
ord_239_.såpe500 1.6 -1.5
ord_241_.bord2 1.3 -3.0
ord_242_.bord1 1.5 -1.8
ord_243_.bord500 2.2 -1.5
ord_244_.bord200 2.2 -0.9
ord_246_.rote1 1.0 -3.2
ord_247_.rote500 1.1 -2.7
ord_248_.rote200 2.0 -1.4
ord_249_.trær2 0.2 -10.0
ord_251_.trær500 0.3 -6.3
ord_252_.trær200 0.7 -3.4
ord_254_.klam1 1.5 -1.6
ord_255_.klam500 2.1 -0.8
ord_256_.klam200 1.8 -0.4
ord_257_.fyre2 0.8 -4.3
ord_258_.fyre1 1.2 -2.7
ord_259_.fyre500 1.0 -2.9
ord_260_.fyre200 1.9 -1.7
ord_262_.slått1 1.1 -0.8
ord_263_.slått500 1.4 -0.5
ord_266_.frosk1 2.2 -1.3
ord_267_.frosk500 1.7 -0.7
ord_268_.frosk200 2.6 -0.6
ord_271_.sykle500 1.4 -2.4
ord_272_.sykle200 1.4 -1.9
ord_274_.lekser1 0.9 -1.9
ord_275_.lekser500 0.9 -1.7
ord_278_.klokke1 1.3 -1.0
ord_279_.klokke500 1.6 -0.6
ord_280_.klokke200 2.0 -0.3
ord_282_.synge1 2.8 -1.3
ord_283_.synge500 2.8 -1.0
ord_284_.synge200 2.7 -0.7
ord_287_.arver500 1.3 -1.2
ord_290_.skolen1 1.0 -1.9
ord_295_.hunden500 1.5 0.3
ord_296_.hunden200 1.9 0.2
ord_299_.padle500 2.0 -0.9
ord_300_.padle200 2.0 -0.5
ord_302_.esker1 0.9 -1.5
ord_303_.esker500 0.8 -0.9
ord_304_.esker200 1.0 -0.1
ord_307_.planke500 0.8 -2.5
ord_308_.planke200 0.7 -3.1
ord_310_.niste1 1.4 -1.5
ord_311_.niste500 2.0 -0.7
ord_312_.niste200 2.0 -0.3
ord_316_.bamse200 2.1 -1.0
ord_318_.hjerne1 1.9 -1.4
ord_319_.hjerne500 1.3 -1.1
ord_320_.hjerne200 1.2 -0.9
ord_323_.lappen500 1.0 -1.9
ord_324_.lappen200 1.0 -1.9
ord_327_.spruter500 1.3 0.9
ord_328_.spruter200 1.1 1.2
ord_330_.bukser1 1.5 -0.9
ord_331_.bukser500 1.7 -0.8
ord_332_.bukser200 2.0 -0.6
ord_335_.genser500 1.3 -0.9
ord_336_.genser200 1.3 -0.6
ord_338_.bakke1 0.8 -3.5
ord_339_.bakke500 1.6 -1.9
ord_340_.bakke200 1.1 -2.4
ord_342_.hjelm1 1.9 -0.8
ord_343_.hjelm500 1.7 -0.3
ord_344_.hjelm200 1.9 0.4
ord_347_.bilde500 1.0 0.0
ord_348_.bilde200 0.8 0.3
ord_351_.glade500 1.5 -1.5
ord_352_.glade200 2.1 -1.1
ord_354_.kosten1 1.6 -1.9
ord_355_.kosten500 1.3 -2.0
ord_356_.kosten200 1.0 -1.6
ord_359_.visper500 1.3 -0.1
ord_360_.visper200 1.8 0.3
ord_362_.kornet1 1.0 -0.7
ord_363_.kornet500 1.0 0.0
ord_366_.silke1 0.6 -1.0
ord_367_.silke500 1.1 -0.3
ord_368_.silke200 0.3 1.0
ord_371_.slave500 1.3 -0.2
ord_372_.slave200 1.4 0.2
ord_375_.teller500 2.6 -0.9
ord_376_.teller200 1.9 -0.9
ord_378_.brøler1 2.9 -0.9
ord_379_.brøler500 2.3 -0.9
ord_380_.brøler200 2.1 -0.5
ord_383_.gnager500 1.1 -0.5
ord_384_.gnager200 1.0 0.3
ord_387_.eksem500 0.9 -1.2
ord_388_.eksem200 0.5 -2.1
ord_390_.kloden1 1.5 -0.6
ord_391_.kloden500 2.0 -0.6
ord_392_.kloden200 1.7 -0.1
ord_394_.flaske1 1.2 -0.1
ord_395_.flaske500 1.4 0.3
ord_396_.flaske200 1.1 0.9
ord_399_.styrke500 1.1 0.0
ord_400_.styrke200 0.9 0.4
ord_406_.skrape1 1.0 -0.5
ord_408_.skrape200 1.4 0.8
ord_411_.salve500 0.9 0.2
ord_412_.salve200 1.6 0.3
ord_414_.lykten1 1.6 -1.7
ord_416_.lykten200 0.9 -2.1
ord_420_.mynter200 1.0 -1.6
ord_422_.drops1 2.1 -1.5
ord_423_.drops500 3.1 -1.2
ord_424_.drops200 2.6 -0.7
ord_427_.våren500 1.6 -1.4
ord_428_.våren200 1.9 -0.9
ord_430_.dukken1 1.0 -2.0
ord_431_.dukken500 1.1 -1.3
ord_432_.dukken200 1.5 -1.1
ord_435_.sukker500 1.0 -2.9
ord_436_.sukker200 1.3 -1.9
ord_442_.luktet1 1.0 -0.7
ord_443_.luktet500 1.4 0.1
ord_444_.luktet200 1.4 0.9
ord_451_.dusten500 1.3 -1.2
ord_452_.dusten200 1.0 -1.5
ord_455_.skøyter500 1.6 -0.1
ord_456_.skøyter200 1.7 0.1
ord_458_.tenker1 2.3 -1.1
ord_459_.tenker500 4.2 -0.6
ord_460_.tenker200 2.5 -0.4
ord_462_.krangle1 2.4 -0.9
ord_464_.krangle200 2.3 -0.1
ord_467_.trasket500 1.6 0.0
ord_468_.trasket200 1.2 0.4
ord_470_.vinduer1 1.0 -1.6
ord_471_.vinduer500 2.1 -0.6
ord_472_.vinduer200 1.1 -0.6
ord_475_.steiker500 0.7 -1.1
ord_476_.steiker200 0.6 -1.3
ord_478_.marsjerer1 1.2 -1.0
ord_479_.marsjerer500 1.9 -0.4
ord_482_.kantarell1 1.4 -1.6
ord_483_.kantarell500 1.5 -0.6
ord_484_.kantarell200 1.7 -0.1
ord_486_.tallerken1 0.8 -1.8
ord_487_.tallerken500 0.7 -1.6
ord_488_.tallerken200 0.6 -0.8
ord_491_.skrutrekker500 0.7 0.4
ord_492_.skrutrekker200 0.5 1.0
ord_494_.glitret1 1.8 -1.0
ord_495_.glitret500 1.7 -0.1
ord_496_.glitret200 1.5 0.0
ord_499_.praktisk500 1.4 0.2
ord_500_.praktisk200 2.0 0.5
ord_503_.speilet500 1.5 -1.2
ord_504_.speilet200 1.2 -0.7
ord_506_.planter1 1.1 -0.6
ord_507_.planter500 0.5 -1.9
ord_508_.planter200 0.8 -1.6
ord_511_.kontanter500 0.8 1.2
ord_512_.kontanter200 0.9 1.5
ord_516_.kanonen200 0.7 0.9
ord_519_.fantastisk500 1.0 -0.8
ord_520_.fantastisk200 0.8 -0.8
ord_523_.transport500 1.0 -1.8
ord_524_.transport200 1.0 -1.6
ord_528_.morderne200 0.7 2.1
ord_530_.prestene1 1.4 -0.7
ord_531_.prestene500 1.4 -0.1
ord_532_.prestene200 1.5 0.3
ord_534_.presentere1 0.4 -1.8
ord_535_.presentere500 0.7 -0.8
ord_536_.presentere200 0.6 -1.2
ord_538_.instrument1 1.8 -1.0
ord_539_.instrument500 1.1 -0.8
ord_540_.instrument200 0.9 -0.8
ord_542_.balansere1 2.2 -0.5
ord_544_.balansere200 1.6 0.4
ord_547_.direkte500 1.3 -0.9
ord_548_.direkte200 1.5 -0.5
ord_551_.ekspertene500 0.6 -1.0
ord_552_.ekspertene200 0.4 -1.5
ord_554_.annerledes1 1.3 -1.2
ord_555_.annerledes500 1.0 -1.2
ord_556_.annerledes200 1.5 -0.5
ord_559_.stativene500 2.3 -0.2
ord_560_.stativene200 1.4 -0.2
ord_564_.stranden200 1.9 -0.2
ord_567_.skjelett500 0.7 -0.9
ord_568_.skjelett200 0.8 -0.3
ord_570_.strutsene1 1.2 -0.5
ord_571_.strutsene500 0.6 -0.7
ord_572_.strutsene200 0.7 0.3
ord_575_.spraglete500 1.8 0.4
ord_576_.spraglete200 1.2 1.2
ord_579_.uhøflig500 1.8 -0.1
ord_580_.uhøflig200 1.9 0.2
ord_583_.hemmelig500 1.1 -2.1
ord_584_.hemmelig200 2.1 -1.3
ord_588_.slåsskamp200 0.9 -0.7
ord_591_.eksplosjon500 1.6 0.1
ord_592_.eksplosjon200 1.2 0.6
ord_595_.reparasjon500 0.7 1.2
ord_596_.reparasjon200 0.8 0.8
ord_599_.pasning500 1.6 -1.1
ord_600_.pasning200 1.5 -0.6
ord_604_.sjenerte200 0.4 -2.5
ord_606_.ordentlig1 1.5 -2.0
ord_607_.ordentlig500 2.0 -1.4
ord_608_.ordentlig200 2.3 -0.8
ord_611_.konsentrasjon500 1.0 -0.8
ord_612_.konsentrasjon200 0.9 -0.3
ord_615_.karakterer500 0.7 -1.4
ord_616_.karakterer200 0.4 -2.7
ord_619_.kjekler500 -0.2 2.2
ord_620_.kjekler200 0.1 -11.3
ord_623_.kraftverk500 2.3 -0.1
ord_624_.kraftverk200 1.5 0.2
ord_626_.overraskelsen1 1.1 -1.0
ord_627_.overraskelsen500 1.3 -0.3
ord_628_overraskelsen200 1.2 -0.1
ord_631_.kraftanstrengelse500 0.5 1.0
ord_632_.kraftanstrengelse200 0.2 2.7
ord_635_.kalenderne500 1.3 -0.4
ord_636_.kalenderne200 0.7 -0.4
ord_639_.systemene500 1.6 -0.6
ord_640_.systemene200 2.4 -0.2
ord_643_.kikkertene500 0.3 2.1
ord_644_.kikkertene200 1.1 0.9
ord_646_.landstedene1 0.5 -0.6
ord_647_.landstedene500 0.4 -2.3
ord_648_.landstedene200 0.3 -1.7
ord_651_.skyskraperen500 1.2 0.6
ord_652_.skyskraperen200 0.7 1.4
ord_655_.tørklær500 1.7 0.2
ord_656_.tørklær200 1.3 0.4
ord_659_.forklærne500 1.2 -1.0
ord_660_.forklærne200 1.2 0.0
ord_663_.ferdighet500 0.5 -2.0
ord_664_.ferdighet200 0.5 -1.6
ord_667_.bagatellisere500 0.6 2.5
ord_668_.bagatellisere200 0.2 7.0
ord_671_.kvalmende500 1.6 -0.1
ord_672_.kvalmende200 1.5 0.4
ord_692_.alarmanlegg200 1.9 0.4
ord_699_.avslappende500 1.1 -1.7
ord_700_..avslappende200 1.0 -1.4
ord_708_.kontraktene200 1.0 1.4
ord_712_.forvekslinger200 1.3 1.0
ord_723_.legetimene500 1.5 0.5
ord_744_.allsidighet200 1.3 0.7
ord_748_.fyrstikkeske200 0.7 -2.0
ord_750_.skylde1 1.7 -1.3
ord_750_.skylde500 1.8 -1.2

We might also look at this visually, with tracelines.

Distribution of discrimination and of difficulty

Items with discrimination less than 0.5

Items with low discrimination (less than 0.5).

##  [1] "ord_010_.sak1"                 "ord_049_.ser2"                
##  [3] "ord_065_.rir2"                 "ord_066_.rir1"                
##  [5] "ord_069_.ris2"                 "ord_109_.søl2"                
##  [7] "ord_158_.møte1"                "ord_177_.hjul2"               
##  [9] "ord_249_.trær2"                "ord_251_.trær500"             
## [11] "ord_368_.silke200"             "ord_492_.skrutrekker200"      
## [13] "ord_534_.presentere1"          "ord_552_.ekspertene200"       
## [15] "ord_604_.sjenerte200"          "ord_616_.karakterer200"       
## [17] "ord_619_.kjekler500"           "ord_620_.kjekler200"          
## [19] "ord_632_.kraftanstrengelse200" "ord_643_.kikkertene500"       
## [21] "ord_647_.landstedene500"       "ord_648_.landstedene200"      
## [23] "ord_664_.ferdighet200"         "ord_668_.bagatellisere200"

Redrawing the graph of proportion correct for items with discrimination above 0.5:

ICC curves for some testlet items