Date of Award


Document Type



Edith Cowan University

Degree Name

Doctor of Philosophy


School of Education


Faculty of Education and Arts

First Supervisor

Associate Professor Deslea Konza

Second Supervisor

Professor Russell Waugh


Visual discrimination, spatial orientation, and recognition of letters and numbers in context are important issues in helping young students achieve good literacy and numeracy standards. Thus, measures of Visual Discrimination of Upper Case Letters (VDUCL), Visual Discrimination of Lower Case Letters (VDLCL), and Visual Discrimination of Numbers (VDN) as well as Spatial Orientation of Letter and Number Pairs (SOLNP), Form Constancy of Letters and Numbers (FCLNP), Letter and Number Sequencing (LNS), Figure Ground of Letters in Words FGLW) and Figure Ground Numbers in Calculations (FGNC) must be linear and uni-dimensional so that student weaknesses can be identified objectively. The Simple Logistic Model of Rasch Measurement was used to order the items on a scale from easy to difficult and the student measures were calibrated on the same scale from low to high. In each scale, items were scored zero (for incorrect) and one (for correct). The student sample N=324 used in this study included pre-primary and primary students in Perth, Western Australia. The initial data were adjusted so that items which displayed misfit statistics were removed from each scale prior to final analysis. The final VDUCL scale (18 items), VDLCL scale (31 items), and VDN scale (14 items) each had a good fit to the measurement model, and were internally reliable. In each scale, there was good agreement about the item difficulties from easy to hard along the scale. Item discrimination and targeting was good. The scales allow teachers to objectively identify the letters and numbers that students find difficult to discriminate and those students who have poor visual discrimination skills of alphabet letters and numbers so that tailored teaching can be applied to those in need.


Paper Location