The purpose of this study was to investigate validity and reliability evidence of Smart Start-Second Edition (Zittel, Kim, & Wessel, 2014) (Smart Start-2) in preschoolers with and without a disability. Thirty-two preschoolers with a disability and 28 preschoolers without a disability participated in the study. The mean age of all participants, preschoolers with a disability, and preschoolers without a disability were 50.98 months (SD = 7.86, range 37 – 64), 53.28 months (SD = 7.28), and 48.35 months (SD = 7.78), respectively. Each participant was asked to perform 12 fundamental movement skills. The participants’ fundamental movement skills performances were filmed and examined with Smart Start-2 and Test of Gross Motor Development-Second Edition (Ulrich, 2000) (TGMD-2) by three trained raters. For validity evidence of Smart Start-2, correlations between data of Smart Start-2 and TGMD-2 were examined with Pearson product-moment correlation coefficients. Intra-rater reliability and inter-rater reliability were also examined using a proportion of agreement, modified kappa coefficient, and intraclass correlation coefficient. Large correlations between data of Smart Start-2 and TGMD-2 were found for total score (r = .89, p < .01), for sum of scores on locomotor skills (r = .92, p < .01), and sum of scores on object control skills (r = .92, p < .01). Across three raters, the average proportions of agreements for intra-rater using Smart Start-2 on all participants, preschoolers with a disability, and preschoolers without a disability were .92, .91, and .91, respectively. Across three raters, the mean of modified kappa coefficients for intra-rater reliability using Smart Start-2 on all participants, preschoolers with a disability, and preschoolers without a disability were .83 (SD = .09, range .52 – 1.00), .83 (SD = .09, range .60 - .96), and .83 (SD = .10, range .52 – 1.00), respectively. The mean of intraclass correlation coefficients for intra-rater reliability using Smart Start-2 on all participants, preschoolers with a disability, and preschoolers without a disability were .96 (95% confidence interval: .94 - .97), .96 (95% confidence interval: .90 - .97), and .96 (95% confidence interval: .93 - .98), respectively.

The average proportion of agreements for inter-rater using Smart Smart-2 on all participants, preschoolers with a disability, and preschoolers without a disability were .86, .87, and .86, respectively. The mean of modified kappa coefficients, across three raters, for inter-rater on all participants, preschoolers without a disability, and preschoolers without a disability were .71 ( SD = .11, range .42 - .89), .72 (SD = .10, range .42- .87), and .69 (SD = .10, range .45 - .89), respectively. The mean of Intraclass correlation coefficients for intra-rater reliability using Smart Start-2 on all participants, preschoolers with a disability, and preschoolers without a disability were .93 (95% confidence interval: .89 - .96), .95 (95% confidence interval: .89 -.97), and .89 (95% confidence interval: .72 - .95), respectively. However, a one-way repeated measures ANOVA showed significant differences of the total scores of Smart Start-2 between raters. The major findings of this study support evidence of concurrent validity and intra-rater reliability and inter-rater reliability of the Smart Start-2 for assessing FMS for preschoolers with/without a disability using 3 trained raters.