The influence of the place-value structure of the Arabic number ...

Error rate
in %
Error Categories (cf. Zuber et al., 2009)
16
12
8
4
0
Combination
Additive
Composition
Inversion Lexical Multiplicative
Composition
Error Type
Figure 1: Distribution of error types as categorized by Zuber et al. (2009) in the reduced sample (n = 94)
of the current study. Please note that the error rates given reflect the respective percent of erroneous
items in reference to all transcoding items and thus are not supposed to add up to 100%.
Magnitude comparison in first grade
An ANOVA showed that both the compatibility effect as well as the (decade) distance
effect were highly significant for errors in the reduced sample [distance: F(1, 93) = 36.97, p <
.001, η 2 p = .28; compatibility: F(1, 93) = 88.61, p < .001, η 2 p = .49]. This indicated that first
graders’ classifications in the magnitude comparison task were more accurate for number
pairs involving a large compared to a small (decade) distance [large: M = 18.1% errors (95%
CI: 14.6% – 21.6%) vs. small: M = 23.2% errors (95% CI: 19.6% – 26.8%)] as well as for
compatible than for incompatible number pairs [compatible: M = 9.6% (95% CI: 7.2% –
12.0%) vs. incompatible: M = 31.6% errors (95% CI: 26.1 – 37.2%].
Please note that even for the most difficult so-called incompatible number pairs
children clearly performed above chance level. As in these trials the larger number contains
the smaller unit identification of tens and units and their associated value is inevitably
necessary to solve the task successfully. Almost 70% correct responses indicate, that the
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