Toward developing a standardized Arabic continuous text reading chart

www.journalofoptometry.org

ORIGINAL

ARTICLE

Toward

developing

a

standardized

Arabic

continuous

text

reading

chart

Balsam

Alabdulkader

∗

,

Susan

Jennifer

Leat

SchoolofOptometryandVisionScience,UniversityofWaterloo,Canada

Received9November2015;accepted29March2016

KEYWORDS Continuoustext charts; Visualacuity; Acuitychart; Reading; Arabic Abstract

Purpose: Nearvisualacuityis anessentialmeasurementduringanoculo-visualassessment. Short durationcontinuous text reading chartsmeasure readingacuityand otheraspects of readingperformance.ThereisnostandardizedversionofsuchchartinArabic.Theaimofthis studyistocreatesentencesofequalreadabilitytouseinthedevelopmentofastandardized Arabiccontinuoustextreadingchart.

Methods:Initially,109Arabicpairsofsentenceswerecreatedforuseinconstructingachart with similar layout to theColenbranderchart. Theywere createdto havethesame grade levelofdifficultyandphysicallength.Fifty-threeadultsandsixteenchildrenwererecruitedto validatethesentences.Readingspeedincorrectwordsperminute(CWPM)andstandardlength wordsperminute(SLWPM)wasmeasuredanderrorswerecounted.Criteriabasedonreading speedanderrorsmadeineachsentencepairwereusedtoexcludesentencepairswithmore outlyingcharacteristics,andtoselectthefinalgroupofsentencepairs.

Results:Forty-five sentence pairs were selected according to the elimination criteria. For adults,theaveragereadingspeedforthefinalsentenceswas166CWPMand187SLWPMand theaveragenumberoferrorspersentencepairwas0.21.Childrens’averagereadingspeedfor thefinalgroupofsentenceswas61CWPMand72SLWPM.Theiraverageerrorratewas1.71.

Conclusions: Thereliabilityanalysisshowedthatthefinal45sentencepairsarehighly compa-rable.TheywillbeusedinconstructinganArabicshortdurationcontinuoustextreadingchart. © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

∗_{Correspondingauthorat:BalsamAlabdulkader,200UniversityAvenueWest,Waterloo,OntarioN2L3G1,Canada.} E-mailaddress:[email protected](B.Alabdulkader).

http://dx.doi.org/10.1016/j.optom.2016.03.003

1888-4296/©2016SpanishGeneralCouncilofOptometry.PublishedbyElsevierEspaña,S.L.U.ThisisanopenaccessarticleundertheCC

PALABRASCLAVE Tablasdetextos continuos; Agudezavisual; Tablaoptométrica; Lectura; Árabe

Haciaeldesarrollodeunacartillaestandarizadadelecturadetextoscontinuosen árabe

Resumen

Objetivo:Laagudezavisualdecercaesunamediciónesencialdelexamenvisual.Lastablas delecturadetextoscontinuosdecortaduraciónmidenlaagudezavisualyotrosaspectosdel rendimientolector.Noexisteunaversiónestandarizadadedichascartillasenárabe.Elobjetivo deesteestudioeseldecrearfrasesdeiguallegibilidad,paraserutilizadaseneldesarrollode unacartillaestandarizadadelecturadetextoscontinuosenárabe.

Métodos: Inicialmente,secrearon109paresdefrasesenárabeparaconstruirunacartillacon undise˜nosimilaral dela tabladeColenbrander.Fueroncreadaspara tenerelmismonivel dedificultadeiguallongitudfísica.Sereunióacincuentaytresadultosydieciséisni˜nospara validarlasfrases.Semidieronlavelocidadlectoraenpalabrascorrectasporminuto(CWPM)y laspalabrasdelongitudestándarporminuto(SLWPM),contabilizándoseloserrores.Seutilizaron loscriteriosbasadosenlavelocidadlectorayloserroresencadafraseparaexcluirlospares defrasesconmáscaracterísticasperiféricas,yseleccionarelgrupofinaldeparesdefrases.

Resultados: Seseleccionaroncuarentaycincoparesdefrases,deacuerdoconloscriteriosde eliminación.Paralosadultos,lavelocidadlectoramediadelasfrasesfinalesfuede166CWPM y187SLWPM,yelnúmeromediodeerroresporpardefrasefuede0,21.Lavelocidadlectora mediadelosni˜nosparaelgrupofinaldefrasesfuede61CWPMy72SLWPM.Suíndicemedio deerrorfuede1,71.

Conclusiones:Elanálisisdefiabilidadmostróquelos45paresdefrasesfinalessonaltamente comparables.Seutilizaránpara construirunatabladelecturadetextos continuosdecorta duraciónenárabe.

© 2016 Spanish General Council of Optometry. Publicado por Elsevier España, S.L.U. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Reading is essential in modern life and is the most com-monrehabilitationgoalforpeoplewithlowvision.1_Inability

toread significantly affectsquality of lifeand soaspects ofreadingareusuallyincludedinvision-relatedqualityof life measures.2---5 _{Reading acuity measurement (acuity for}

textor words) is important in assessing a patient’s read-ingperformance6 _{and inunderstanding the impactof eye}

disease.7---9 _{Although there is a good correlation between}

distanceletteracuityandwordortextacuity,10---12_theyare

notequal,10,13,14 _{and word or text reading acuity is more}

related to everyday reading tasks.15,16 _{Charts using short}

durationcontinuoustextareconsideredabetter represen-tationofaperson’svisionforeverydayreadingthancharts using unrelated words15,16 _{as reading short duration}

sen-tencesincludescognitiveandvisualfactors,e.g.effectsof contextandcrowding.6_{Theyquicklyassessapatient’snear}

readingacuityandcanalsomeasuremaximumreadingspeed andcriticalprint size(the smallestprint toachieve max-imumor near maximum reading speed).6 _{These measures}

indicatethepotentialforreadingsmallprintfluently,and areusedtoestimatetherequiredmagnificationforreading in patients withlow vision. The use of standardized sen-tencesandlayoutisimportant,sothattheprintsizeisthe onlyparameterthataffectsthethreshold,andnot variabil-ityinthetextdifficultyorcrowdingeffects,soastoensure reliableandrepeatedresults.17---20

The concept of using standardized sentences of equal lengthanddifficultywasfirstintroduced byLeggeand co-workers in1993 anddeveloped intotheMNREAD charts.21

Radneretal.22_{developedtheconceptfurther,creating}

sen-tenceswhichwereequalintermsoflexicalandsyntactical difficulty, wordlengthandpositioningof wordswithinthe sentence.Continuoustextreadingchartsarenowavailable inmanylanguages.19,20,23---28_{Arabicisrankedasthefifth}

spo-kenlanguage(innumberoffirstlanguagespeakers)andis spokenin60differentcountriesglobally,withapproximately 237millionnativespeakers.29_{Despitethisthereisnoshort}

duration standardized Arabic reading acuity chart. There havebeenanumberofattemptstodevelopArabicdistance andnearlettervisual acuitycharts,30---35 _{butnone ofthem}

havebeenproducedorarecommerciallyavailable.Thelack of standardized continuous text reading charts has made theuseofnon-standardizedchartsverycommon.Theseare eithercreatedandprintedbycliniciansorfreelydistributed byeye-carecompaniesforadvertisementpurposes. These chartsusesentencesthathavenotbeendeveloped accord-ingtotherecommendationsforstandardizedreadingacuity charts6,16,17,36_{andtheyhavenotbeentestedforreliability}

andrepeatability.Itisimportantthatchartvariables,such astexttypeface,textdifficulty,andtextlengthshouldbe equalfordifferentacuitylevelssothatcomparableresults aregivenwithdifferentversionsofthechart.Theone stan-dardizedreadingchartinArabicistheIReSTtexts,24_butthis

acuity.Itis composedofparagraphs oftextinonesizeof print.

Readingchartsareavailableindifferenttypes.They dif-ferin their design (i.e. unrelated words, mixedcontrast, longpassages)24,25,37,38 _{andtest purposes(reading}

compre-hension, silent reading).39,40 _{The ultimate purpose is the}

developmentof thefirst standardized shortduration con-tinuous text near reading charts in Arabic. This type of chartiscommonlyused,iseasilyadministeredclinicallyand givesresults whicharerelatedtodailyreadingmaterial.6

Thefinallayoutwaschosentobesimilartothe Colenbran-derchartswhichusespairsofequal lengthsentencesin a logarithmic size progression. Although hissentences were createdbasedoncertaincriteria(e.g.wordsnolongerthan 10letters),theywerenotformallytested fordifficultyof reading. Retrospectively, they were found to be of grade 4difficulty(Colenbrander,personalcommunication).There aretwoapproachestothedevelopmentofstandardized sen-tences. Either sentences aregenerated that arematched accordingtothenumberofcharactersandphysical length andthenempiricallytested6,21 _{orsentencesaregenerated}

tohaveequallexicalandsyntacticaldifficulty,wordlength andpositioningofwords.22 _{Asthisisthefirstchartin}

Ara-bic, we chose the former method.The aim of thisinitial studyistocreateArabicsentencesofequalreadabilityto beusedinthedevelopmentofthesecharts.Sincethe char-actersandwritinginArabicarecomplexandquitedifferent fromRomanletters,therearemanydecisionstobemade regardingthechoiceoftypefaceandprintcharacteristics. This paperdescribestherationale for thesedecisionsand thecreationofasetofsentenceswithgoodreliability.

Methods

Choiceoftypeface

It has been suggested by other researchers6,37,41 _{that the}

optimum font would be the most commonly usedfont in everydayprintedmaterialsuchasnewspapers,magazines, books,etc.However,mostArabicnewspapersusetheirown specially designedfont,whereas mostEnglishnewspapers use commonly available proportionally spaced serif fonts (e.g. Times New Roman).6 _{The exact fonts used in}

popu-larArabic newspapersarenotavailable, foruse byothers andthus, couldnotbeused.Therefore,the closest avail-ablefontinMicrosoftWord© _{waschosen,whichwasArabic} TimesNewRomanfont.This choicehadadditional advan-tages.Firstly,itisfrequentlyusedinreadingchartsofother languages.6,19,24,26,28_{Secondly,ArabicTimesNewRomanfont}

in MicrosoftWord© _{does notuse ligatures, whichare} spe-cific Arabic font characteristics. A ligature is used when more than onecharacter is joined to forma singleglyph (areadablecharacterorshape)(Fig.1)andtheycannotbe eliminated.Theuseofaligaturecouldaffectthe readabil-ity,asit changestheshapeandheightofawordandmay causemorecrowding,especiallyinsmallfontsizesandfor peoplewithlowvision.Thirdly,ithasbeenshownthatArabic TimesNewRomanresultsinenhancedreadingperformance comparedtoCourier.42

Aseconddecisionwasnottousevocalizationmarks,as theyareabsentineverydaymaterials,43,44_{likenewspapers.}

5

A

B

4 3 1+2+3+4 5 2 1

Figure1 Demonstration ofArabic typefacecharacteristics. (A)Asampleofafive-letterword(whichmeanscommunity)in TimesNewRomanfont.Thenumbers1---5indicateeachletter. (B)ThesamewordwithaligatureusingArabictypesettingfont.

Experiencedreadersfluentlyreadunvocalizedtextbyusing contextualclues.44 _{Vocalizationmarksareusually usedto}

clarifythe pronunciationof certainwords. Theyare com-monly used as learning aids for children and beginner readers, in dictionaries and some literary materials,44 _in

poetry43 _{and the Quran, where it is imperative to avoid}

misreading.However,generalreadabilityimproveswithout vocalizationmarkswhen inconjunction with thesimplest font.43

Creatingasetofsentenceswithhighreliability

The ultimate goal is to produce three versions of Arabic continuoustextnearvisualacuity chart,sothat repeated testingispossible (e.g.binocularlyandmonocularly).The chartswillbedevelopedtobesimilarindesigntothe Colen-brandernearacuitycharts,inwhicheachfontsizehasapair ofunrelated sentencesdesigned tobeof thesamelength anddifficulty,withthesamenumberofcharacters includ-ingspacesandendingwithafullstoporquestionmark.For theArabicchart,itisplannedthateachchartwillhave fif-teenpairsofpairsofsentencesinalogarithmicprogression ofdecreasingprintsize.Ultimately,forty-fivepairsof sen-tences areneeded toproduce thethree differentcharts. Candidatesentenceswereinitiallydevelopedby BAbased onthe contentand the vocabulary of gradethree Arabic schoolbooksandwiththehelpoftwoEgyptianArabicschool teachers.Thesentencesineachpairwereindependentof each other in their semantic content and were designed

There is a doctor who treats sick students in our little school. The students practice sports and play soccer in the park.

Elephants are large animals that live in the forest and eat vegetation. Most people love the view of the moon at the end of the month.

Figure2 Exampleofapairofsentences.TheEnglishisnot aliteral,word-for-wordtranslation,butasemantictranslation i.e.onethatconveysthemeaninginnaturalEnglish.

sothateach isprintedonaseparate line.Theywere cre-atedatapproximatelythesamelevelofdifficulty,theexact samephysicallength, andthesamenumberof characters with spaces for each pair of sentences (102 characters). The number of words in each pair ranged from 16 to 22 andnowordshadmorethantenletters(Fig.2).Two sam-plesentencesinArabicwiththeirEnglishtranslationcanbe seeninFig.2.Thesentenceswerethencheckedbythree ArabiclanguagespecialistsfromSaudiArabiafor grammat-icalandsentencestructureaccuracy.Lastly,thesentences were sent to three other readers, from Libya, Egypt and Moroccotocheck thatthe sentencesdidnot contain cul-tural inaccuracies in these countries. The use of people from several Arabic countries insured that the sentences are understandable across different Arabic countries and cultures.

ThesentenceswereprintedinMicrosoftWord©_using Ara-bic Times New Roman font, in a font size that was well above the thresholds of participants with normal visual acuity, so that reading accuracy and speed would not be limited by vision, but by the readability (difficulty) of the text. Thirty-five point size was chosen, which is the largestfontthatwouldfiteasilyonastandard8.5by11in. (21.6cm×27.9cm) page in landscape orientation. Since thereisnomeasurementofthesizeofprintinArabic simi-lartothe‘‘x’’height45_{inEnglish,thisprintsizecannotbe}

compareddirectlywithRomanletterpointsizesorxheights. However,inthecurrentstudythislackofclearcomparison isnotexpectedtohaveanimpact,astheprintsizewasnot varied. Allthesentenceswere printedin thischosen size andofthesamefont.Determininganequivalentofthe‘‘x’’ heightwillbethesubjectoffuturestudies.Eachpairof sen-tenceswasprintedinlandscapeorientationatthecenterof an8.5in.×11in.separatepageusing1.15linespacingand allpageswereinserted ina binderfolder.The folder was supportedonawoodenreadingstandtoeasilydisplaythe sentences.Astandard readingdistance of 40cmwasused foradultsand30cmforchildren.Athreadmeasuring30or 40cmwasattachedonthesideofthestandtomeasurethe exactreadingdistanceandwasusedtofrequentlycheckthe readingdistanceandtokeepitconstant.

Participants

The sample consisted of 69 native Arabic speakers from twelvedifferentcountries.Snowballsamplingwasusedto recruitfifty-threeadultsfromtheUniversityofWaterlooand fromthecityofRiyadhinSaudiArabia.Theinclusion crite-riawerebeinga fluentArabicspeaker,VA 6/7.5or better (withhabitualcorrection)andnoknowneyedisease.

The adult participants were agedfrom 18 to 60 years (mean31.1)andincluded31malesand22females.Interms oftheireducation,41%hadcompletedhighschool,29%had completedfirstpost-secondarystudies,and30%ofthe par-ticipantshadcompletedpost-graduatestudies.Forthechild sample, seven male and ninefemale grade three partici-pantswererecruited.

Distancevisualacuitywasmeasuredbinocularlyusingan EDTRSlogMARchart(forthosewhocouldrecognizeRoman letters)oraLEASymbols® _{MassachusettsFlipChartat3m} (forthosewhodidnotknowRomanletters).Nearvisual acu-itywasmeasuredusingaSloanLetterNearVisionCardora Leasymbols®_{nearvisioncardat40cm.}

GradethreestudentswererecruitedfromAltarbiya Alis-lamiyaSchoolsinRiyadh,SaudiArabia.Theinclusioncriteria wereasfollows:age7---8years(gradethree),fluentArabic speaker,noknownlearningor readingdisabilityorspecial needs,noAutismorbehavioralissuesasreportedbythe par-ents.Distancevisualacuitywasmeasuredbinocularlyusing theLEASymbols® _{MassachusettsFlipChartat3mandnear} visual acuitywasmeasured withLeasymbols® _{near vision} cardat40cm.

Procedure

Theluminanceofthepaperwassettobe≈130cd/m2_. Par-ticipants’ocularandgeneralhealthhistorywasrecorded.

Theorderofthesentencepairswasrandomizedforeach participantandallparticipantswerevideotapedwhile read-ingthesentences.Participantswereinstructedtoreadaloud asfast aspossiblewithout sacrificingaccuracy but notto worryiftheydidmakeanerror,i.e.theywereencouraged tokeepreadingeveniftheyrealizedtheyhadmadeanerror. Tofamiliarizeparticipantswiththereadingprocedure,they began byreading threedemonstration pairs ofsentences. Flipping pageswasperformed bythe examiner tocontrol thereadingdistanceandthepresentation.The numberof errorsforeachsentencepairwasrecordedforeach partici-pant.Thetimetakentoreadeachpairofsentencesandthe numberoferrorsweredeterminedafterthereadingsession byreviewingtheparticipants’videos.Thisallowedan accu-ratecalculationofthespeedin‘‘correctwordsperminute’’ (CWPM,seebelow).

Thestudy wasapprovedandreceivedfullethics clear-ance from the Office of Research Ethics, University of Waterloo.Allparticipantsgavetheirwritteninformed con-sentpriortoparticipationinthestudy.

Dataanalysis

Nineteensentencepairswereeliminatedbeforecarryingout anyformalanalysis.Thisisbecausealargenumberof par-ticipants madeseveralerrorswhile reading thembecause

ofthetextfloworstumbledbecauseofdifficultiesin pro-nunciation and/or commented thatthe sentencesdid not makegoodsense.Fortheremainingninetysentencepairs, themaximumandmeannumberoferrorsandthestandard deviationoferrorswerecalculatedforeachsentencepair. The following measures of readingspeed were calculated foreachparticipantforeachofthe90remainingsentence pairs.

Correctwordsperminute(CWPM)

Readingspeed(CWPM)₌60_×numberofwords−numberoferrors

timeinseconds

CWPM wasincluded asit is more likelyto be usedby cliniciansthan SLWPM(below).However,CWPMcanresult inmorevariability6,16 _{inreadingspeedbecauseofthe}

vari-ability of word length in different pairs of sentences. So thereforeSLWPMwasalsousedtocalculate readingspeed inthisstudy.

Correctstandardlengthwordsperminute(SLWPM)

Measuringreadingspeedinstandardlengthwordshasbeen used in reading speed research in English.12,46,47 _{To the}

authors’knowledge,therearenopublisheddatagivingthe average or standard word length in Arabic. This was cal-culated froma selection ofthreetypical typesof articles (general,sportsandpolitics).Oneofeachtypewasselected fromthirteenArabicnewspapers,whichoriginatedfromten differentArabiccountries(i.e.atotalof39articles).In addi-tion,threearticlesweretakenfromonewoman’sandone man’s magazines (totalof sixarticles). The average word lengthintheseArabicarticleswas4.7characters.Forthis study,theaveragewordlengthinArabicwasroundedtofive characters.Forcomparison,theaveragewordlength (with-outspaces) wasalso4.7inthe 90pairsof sentencesthat wereanalyzedforthisstudy.

Sincethereareexactly20.4standardwordsineach sen-tence,readingspeedincorrectstandardlengthwords per minute(SLWPM)wascalculatedasfollows.

Readingspeed(SLWPM)=60×20.4−numberoferrors timeinseconds

Finally, allreading speedvalueswere convertedtolog unitsandthemeanreadingspeedandthestandard devia-tion(SD)(calculatedfor both CWPMandSLWPM)for each sentencepairwascalculated.

Selectingsentenceswithsimilarreadability

characteristics

Thedataof childrenandadultswereanalyzedseparately. As there was a larger sample of adults, the adult data were usedfirst tofinalize agroup of sentence pairs with equal readabilitycharacteristics, anda higherpercentage ofsentenceswereeliminatedbasedontheadultdata.The distributionsof readingspeedwerecheckedfor normality usingtheD’Agostino&Pearsonomnibusnormalitytest.Pairs

of sentences were eliminated according to the following criteria:

• ToequalizethereadingspeedsforbothCWPMandSLWPM of the sentence pairs, the 90% interval wascalculated (mean±1.645×SD) and all sentences that fell outside thisrange(i.e.inthehigherandlower5%).

• To eliminate thosesentence pairs withmorevariability inreadingspeed,thoseinthehighestpercentile(10%)of theSDofCWPMandSLWPM.

• Toeliminatethosesentencepairswhichgavemoreerrors, thosein the highest percentile of the meannumber of errors.

• To eliminate thosesentence pairs withmorevariability inerrors,thosewiththehighest percentileoftheSDof errors.

• To eliminate those which gave higher errors, sentence pairs in the highest percentile (to the nearest integer) ofthemaximumnumberoferrors.

Sentence pairs wereeliminated in a two-stepprocess. Firstly,eachcriterionwasappliedseparately,andtheresults werereviewedtoensurethattheseeliminationswouldnot resultintoomanysentencepairsbeingeliminatedfromthe total.Thiswasnotthecaseandsothenallthecriteriawere appliedandany sentencepair thatmet anyof theabove criteriafortheadultdatawereeliminated.Atthisfirststep 35sentenceswereeliminated.

Secondly, based on the remaining sentences, a similar analysiswas performed using the child data to eliminate anyobviousoutliers.The 95% intervalforSLWPM was cal-culated(mean±1.96×SD)andpairsofsentencesthatfell outside this range (in the highest and lowest 2.5%) were eliminated.Additionally,pairsofsentenceswhichgavethe highest percentileof the mean number of errorsand the highestpercentileof themaximum numberoferrorswere eliminated.

TheCronbach’salphacoefficientwascalculatedforthe finalsetofsentencepairstodetermineinter-item(sentence pair)consistency/reliability.

Results

Adults’ distance and near visual acuity ranged between −0.18 to 0.12 (mean −0.11logMAR) and −0.28 to 0.10logMAR (mean−0.09logMAR), respectively. The chil-drens’ distance and near visual acuity ranged between −0.10to0.20(mean0.01)and−0.12to0.10logMAR(mean 0.02)respectively.

Fortheadultdata,thedistributionsofthetwomeasures ofreadingspeedwerebothnormallydistributed(p=0.87for CWPMandp=0.36for SLWPM).Thirty-fivesentenceswere eliminatedafterapplyingalltheeliminationcriteriaonthe adultdata.Theresultsoftheeliminationprocessforadults areshowninFig.3whichshowsreadingspeedofadultsfor all90sentencepairsbeforeandaftereliminationaccording toallelimination criteria. Fig.4 shows histogramsof the meannumber of errorsfor adults for each sentence pair andthemaximumnumberoferrorsforeachsentencepair. The childrens’ data were analyzed subsequently. Based on the remaining 55 sentences, the 95% interval

2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 0 10 20 Reading speed CWPM Sentence number

A

B

D

C

Sentence number Sentence number Sentence number Reading speed SL WPM 30 40 50 60 70 80 90 0 10 20 30 40 50 60 70 80 90 0 5 10 15 20 25 30 35 40 45 0 5 10 15 20 25 30 35 40 45 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5

Figure3 Meanreadingspeed(logunits)foreachsentencepair(adults).Redlinesshowthe90%intervalofall90sentences.(A) ReadingspeedinCWPMforall90sentencespairs.(B)CWPMforfinalsetofsentencepairsusingallexclusioncriteria.(C)Reading speedinSLWPMforall90sentencespairs.(D)SLWPMforfinalsetofsentencepairsusingallexclusioncriteria.

20

A

C

B

D

15 10 5 0 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 55 1 2 3 4 1 2 3 50 45 40 35 30 25 20 15 10 5 0 55

Final average number of errors

Final maximum number of errors Average number of errors

Maximum number of errors

Number of sentences Number of sentences 50 45 40 35 30 25 20 15 10 5 0 20 15 10 5 0

Figure4 Histogramsofmeannumber oferrorsandmaximumnumber oferrorsfor eachsentencepair (adults).(A)Average numberoferrorsforall90sentencespairs.(B)Averagenumberoferrorsforfinalsetof45sentencepairs.(C)Maximumnumberof errorsforallsentencepairs.(D)Maximumnumberoferrorsforfinalsetof45sentencepairs.

2.4 0 5 10 15 20 Sentence number Reading speed SL WPM 25 30 35 40 45 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5

Figure5 SLWPM(logunits)forchildrenforthefinalsetof45 sentencepairsusingallexclusioncriteria.

(mean±1.96×SD)of children’s reading speed was calcu-lated in SLWPM. Sentence pairs that fell outside the 95% intervalwereeliminated.Alsosentencepairsinthehighest 10%ofaverage numberof errorsandmaximum numberof errorswereexcluded.Finalreadingspeedforthechildren inSLWPMisshowninFig.5andthefinalnumberoferrors andmaximumnumberoferrorsareshowninFig.6.

Thesecondeliminationprocessresultedin47sentences. Thisallowedustoeliminatetwomoresentencestoobtain45 sentences.Thesentencewiththenexthighestmeannumber oferrorsandthesentencewiththenexthighestmaximum numberoferrorbasedonthechildren’sdatawereexcluded. Forty-fivesentence pairsremainedafterthese elimina-tion procedures and these will be used to create three versionsofanArabiccontinuoustextreadingchart.Table1 showsthesummaryofthefinalsentencepairsafter elimi-nationforadultsandchildren.

TheCronbach’salphacoefficientwascalculatedto sup-portthatthefinalsetofsentencepairswerereliabletobe usedintheconstructionofthenewArabicreadingcharts. The Cronbach’s alpha for the final set of sentence pairs in CWPM and SLWPM was 0.986 for adults and 0.996 for children.

Theaveragereadingspeed(CWPM)ofadultparticipants rangedfrom117.7to252.4(mean166.4±34.3)andfor chil-drenthisrangedfrom20.5to103.6(mean60.6±27.9).

Discussion

TheaimofthisstudywastocreateArabicsentencesofequal difficultytobeusedinthedevelopmentofthefirst standard-ized Arabic shortduration continuous text reading acuity charts.The chartswillbedesignedtomeasurenearvisual acuityaswellasreadingspeed,criticalprintsizeand read-ingacuityforchildrenandadults.Itis intendedthateach chartwillhavefifteendescendingprintsizesina logarith-micprogression,whichwillallowprintthatislargeenough tomeasurenearvisualacuityinpatientswithlowvision.

Thesentencesweretestedwith35pointsize(pt)print, whichmaysoundlargeinthecontextofRomanprint. How-ever,Arabicisapproximately2×smallerthanRomanprint (i.e. 35 point in Arabic appears smaller than 35 point in Romanprint) sowhenthisistakenintoaccount,theprint sizeisnotabnormallylarge.Additionally,preliminarydata showedthat reading speed for 35 point print in Arabic is withinthe rangeof print sizes that gives maximum read-ingspeed.Thesepreliminaryfindingsindicatethatusing35 pointprintfortestingsentencesdidnotintroducedaceiling effectforreadingspeed.

Sofar,standardizedcontinuoustextchartsareavailable in nineteen languages, or more. Most of these languages useRomanscript.Recently,researchershavedevelopedthe IReST text charts24 _{which are standardized long passage}

readingchartsavailable inseventeen differentlanguages, includingArabic.Thesechartsaredesignedwithoneprint sizeonly(1M)tomeasureandassessreadingspeedand com-pare it across different languages. The developers based the texts for different languages on the original German IReSTchart,withmodificationsforlanguagedifferencesi.e. they did not create new text for each language.25 _They

havereported differencesin text lengthacross languages duetodifferencesbetweenalphabeticandnon-alphabetic languages.24 _Manyscholars16,19,26_{holdtheviewthatdirect}

translation of sentences from an existing standardized charttoa differentlanguageis oftenimpractical andnot idealbecauseeachlanguagehasspecificorthographic dif-ferences. Grammar, spelling, average word length, word

10

_A

15

_B

10 5 0 8 6 4 2 0 0.8 1.0 1.2 1.4 1.6 1.8

Final maximum number of errors Final average number of errors

Number of sentences

2.0 2.2 2.4 2.6 2.8 3 4 5 6 7 8

Figure6 Histogramsofthefinalsetof45sentencepairs(children).(A)Averagenumberoferrors.(B)Maximumnumberof errors.

Table1 Mean(range)ofthefinal45sentencepairs(basedonadultandchilddata). Adultdata

Readingspeed(CWPM) Readingspeed(SLWPM) Averagenumberoferrors Maxnumberoferrors Log 2.22(2.16---2.27) 2.26(2.22---2.31)

0.21(0.02---0.43) 1.73(1.00---3.00) Linear 166.3(145.1---187.6) 183.6(167.0---203.8)

Childdata

Readingspeed(SLWPM) Averagenumberoferrors Maxnumberoferrors Log 1.81(1.69---1.90)

1.71(0.88---2.76) 5.51(3.00---8.00) Linear 63.9(48.9---79.7)

breaks,hyphenation,andtheuseofvocalizationmarksare

alldifferent andall make directtranslation difficult. The

TurkishlanguageusesthesameRomancharactersasEnglish,

plussevenextralettersthataremodifiedtomeettheunique

phoneticrequirementsofthelanguage.InGreekthe

differ-entlyformedCyrillicalphabetisused.Incomparison,Arabic

usesacompletely differentalphabet.Unlike Roman

char-acters,where lettersarewritten individually fromleftto

right,Arabiciswrittenfromright toleftinacursive style

only. These factors make translation inappropriate in the

developmentof consistent sentences. In ordertoachieve

uniformityin thetotal numberof charactersand physical

lengthontheline,newsentenceshavetobecomposedfor

somelanguages.19,26

Therefore, in the present study we developed new sentencesin Arabic, which were composed following the layoutof the Colenbrander chart. The present study uti-lizedmethodologiessimilartootherstudiesinthecreation and testing of sentences.16,19,26 _{It is a common practice}

touse schoolbookstocreatesentencesofacertaingrade level.ThisapproachwasusedfortheGreekMNREADchart,19

MNREADTurkish chart26 _{andUiTM-MrwMalaychart.}28

Lan-guageexpertswereconsulted toverifythe correctnessof grammarandsentencestructuresinthesecharts19,24---26_and

layreadersalsocheckedforculturaldifferences.

Videotaping waschosen asamore accuratemethodof timing tomeasure reading speed than the use of a stop-watch.Anumberofpreviousstudies20,48---50_{havebasedtheir}

readingspeedmeasurementsonvideooraudiotaperecords, which reduces variability in reading speed measurements comparedtotheuseofastopwatch,asthemeasurementis doneafterthereadingsession.16 _Rubin51 _{identifiedseveral}

factors,includingexaminerreactiontimeintimingeach sen-tence,falsestarts,and thehabitof self-correcting errors byreaders,whichmayaffect readingspeedmeasurement precisionand repeatabilitywitha stopwatch.In addition, thedecision about errorsmust be made in realtimeand cannotbere-checked,asitcan withvideotaping. Brussee etal.16 _andRubin51 _{discussedhowthenumberof}

examin-ers/ratersusedinastudyandtheirtrainingmaycontribute tothevariabilityofthereadingmeasurement.Inthecurrent study,onlyoneexaminer(BA)carriedoutreadingsessions andreadingspeedcalculationsfromrecordedvideos.

Adults19,20,23---25,27,28 _{of varying educational levels and}

grade 3 children19,26 _{were recruited to measure the}

reli-abilityofthesentences,sothatthechartscanbeusedfor

peoplewithreadingability ofgrade3upwards.The Cron-bachalphaofthesentencepairsinthepresent studywas 0.99forbothadultsandchildren.Thiscomparesvery favor-ablytothestudybyRadneretal.,20_{inwhichthecalculated}

Cronbachalphacoefficientwas0.98forshortGerman sen-tences, whichwere usedtoconstructtheGerman Radner readingcharts.

The adults’ average reading speed in CWPM obtained in the current study ranged between 118 and 252 (mean 166±34).The onlyother studywhichgives readingspeed for Arabic reading test charts is the study by the IReST group,24 _{whichreportedan averagereadingspeedinWPM}

of138±20,whichissimilartothecurrentstudy.This sim-ilarityisdespitedifferencessuchasthegradeleveloftext (theIReSTusedahighergradelevel),thesizeoftheprint (IReSTused1M)andthefactthatIReSTdidnottakeerrors intoaccount.AlsaiariandAzmi52_{reportedanaverage}

Ara-bicreadingspeedfor Universitystudentsreadingpassages withoutvocalizationmarksof164.27±7.57WPMand128.98 SD±5.47fortwodifferentArabicfonts,whichissimilarto thereportedreadingspeedhere.

TheseresultsindicatethatreadingspeedforArabicmay besloweronaveragethanfor English.Thisdifferencewas reportedbytheIReSTgroup,24 _{readingspeedinwordsper}

minutein ArabicwaslowercomparedtoEnglishand com-paredtoallotheralphabeticlanguagesthattheymeasured. InfactEnglishresultedinthehighestreadingspeedofallthe languageswhenmeasuredinWPM(228±30wpminEnglish comparedto138±20WPMinArabic).

Inthecurrentstudy,children’sreadingspeedsinCWPM rangedbetween20and104(mean61±28).Theonly compa-rabledataisthatofHussien,53_{whichshowedamedianoral}

readingrateof90WPM in6thgradechildren.The obvious reasonforthehigherreadingrateinHusseins’sstudyisthe higher grade levels of the children (6th versus 3rd grade readers).However,comparingreadingspeedsbetween dif-ferent studies must be interpreted with caution. Testing methodsandproceduresplayalarge roleontheresulting averagereadingspeed,andmayexplainthedifferencesin theresults.16

Developingthenewcharts

Prototypes ofthe final chartswere printedon11 by14in sheets,whichisasimilaroverallsizetotheMNREADchart.

Point size 32 25 20 16 12.5 10 8 6 5 4 3 2.5

Figure7 Chartlayoutwithcandidatesentences.

Theywereprintedinlandscapeorientationtoaccommodate thelargestfont.Thefontsizerangedfrom63.5ptto2.5pt. Thelargestthreepairsofsentenceswereprintedononeside andtwelvesmallerpairsofsentenceswereprintedonthe otherside.Sentenceswerearrangedwithsizeprogression inincrementsof0.1logsteps.Thetypicallayoutofoneside ofthechartisshowninFig.7.

Preliminary data with twenty bi-lingual participants compared near reading visual acuity between the newly designedArabicchartsandthestandardizedMNREADEnglish chart. The results showed that most of the participants’ threshold with the Arabic charts was 4 point size which is the third sentence from the bottom of the chart (i.e. the third smallest size). This gives two levels below the acuitylevel of almost all participants.This similarto the MNREAD chartwithwhich thereading acuityofmost par-ticipantswas−0.1logMARwhichisthefifthsentencefrom thebottomofthe chart.Note thattheMNREAD charthas 19sizelevelscomparedto15levelsonthenewlydesigned Arabic charts. Thus the number of supra-threshold levels of the Arabic chart will be 12 compared to 14 for the

MNREAD, ensuring that sufficiently supra-threshold print sizesareavailabletomeasureathresholdinpatientswith lowvision.

Conclusions

Thecurrentstudydevelopedanddeterminedthereliability ofa groupof forty-five sentencepairs which have similar readabilitytooneanother andwhich willbeusedto cre-ateshort duration Arabic continuous text reading charts. Wehavealsopresenteddataonreadingspeedsfor Arabic textforbothadultsandchildren.

Conflicts

of

interest

Theauthorsreportnoconflictsofinterestandhaveno pro-prietaryinterestinanyofthematerials mentionedinthis article.

Acknowledgements

WewouldliketothankDr.MosaAlawees,HamadaAhmed andFateh Tallugefor their help insentence creation. Dr. MohammedAlmullaandDr.SulaimanAlayunifortheir gram-maticalrevisionof thesentences. Majeda Alsumaiforher assistance in recruiting participants from Altarbiya Alis-lamiya Schools. Also, we would like to thank Professor Gordon Legge for his valuable advice and support. This researchwasfundedbyKingSaudUniversity,SaudiArabia.

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