The purpose of this meta-analysis was to examine if individuals with dyslexia (DYS) have a deficit in orthographic knowledge. We reviewed a total of 68 studies published between January 1990 and December 2019, representing a total of 7215 participants. There were 80 independent samples in the chronological-age (CA)-DYS comparison and 33 independent samples in the comparison between DYS and reading-level (RL) controls. A random-effects model analysis revealed a large effect size (Cohen’s d = 1.17) for the CA-DYS comparison and a small effect size (Cohen’s d = 0.18) for the RL-DYS comparison. In addition, we found significant heterogeneity in the effect sizes that was partly explained by the level of orthographic knowledge (effect sizes being higher for lexical than sub-lexical orthographic knowledge). These results suggest that individuals with dyslexia experience an orthographic knowledge deficit that is as large as that of phonological awareness and rapid automatized naming reported in previous meta-analyses.

这项荟萃分析的目的是检查患有阅读障碍（DYS）的个人在拼写方面的知识是否不足。我们审查了1990年1月至2019年12月之间发布的68项研究，代表7215名参与者。在时间年龄（CA）-DYS比较中有80个独立样本，在DYS和阅读水平（RL）对照之间的比较中有33个独立样本。随机效应模型分析显示，CA-DYS比较的效应量较大（Cohen d = 1.17），效应量较小（Cohen d= 0.18）进行RL-DYS比较。此外，我们发现效果大小存在明显的异质性，这在一定程度上是由拼字知识的水平所解释的（词汇大小高于次词汇拼写知识）。这些结果表明阅读障碍的人正字法知识的缺失与以前的荟萃分析中报道的语音意识和快速自动命名一样严重。