Browsing by Author "Vartiainen, Liisa"

Aims. The aim of this Master’s Thesis (Special Education) is to evaluate reliability and validity of the CodyTest in Finland with grade 2–4 children. The CodyTest is designed to identify children who are at risk for mathematical learning difficulties. The test’s reliability and validity has been evaluated in German sample, but not before with Finnish sample. Methods. Fivehundredthirteen children participate the study. Data was collected during years 2016–2017 and that was part of teacher’s training program of Niilo Mäki Instituutti. The teachers used the test with children in their own classes. The data is owned by Niilo Mäki Instituutti, which granted it to be used in this study. The construction of CodyTest was evaluated by confirmatory factor analysis (CFA) and the reliability was evaluated by Cronbach’s alfa. Configural freqvency analysis and Pearson’s correlation was used to assess if the results of CodyTest were stable over seven months. The concurrent validity of CodyTest was evaluated with correlations between CodyTest and other mathematical skills tests. Results. The structural equation model which was found by CFA has a good fit (X^2 (33)=99.427, p<0.001, CFI=0.96, TLI=0.93, RMSEA=0.06). The analysis showed that CodyTest has two latent factors, namely “subitizing and comparing” (α=0.75) and “number sequence and basic arithmetic skills” (α=0.74). The composite test’s reliability was 0.77. The stability of CodyTest’s scores were reliable between seven months, the test-retest correlations were high, and it was possible to identify low performing children both times. The two factor and composite scores were correlating with mathematics skills test total scores. The results in this thesis show that the reliability and validity of CodyTest are good in Finnish sample.