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

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Again, a multiple stepwise regression analysis was conducted to evaluate <strong>the</strong><br />

differential <strong>influence</strong>s <strong>of</strong> <strong>the</strong> variables depicted in Table 2, Panel B on overall addition<br />

performance in third grade. <strong>The</strong> final model [R = .44, adjusted R 2 = .16, F(4, 90) = 6.99, p <<br />

.001, f 2 = .23] included <strong>the</strong> three predictors a) <strong>number</strong> <strong>of</strong> pure inversion transcoding errors, b)<br />

compatibility effect, and c) (decade) distance effect (see Table 3). Inspection <strong>of</strong> <strong>the</strong> beta<br />

weights indicated that children who committed more pure inversion transcoding errors in first<br />

grade also exhibited a higher overall error rate in <strong>the</strong> third grade addition task. Similarly,<br />

children with a relatively large compatibility effect in <strong>the</strong> first grade magnitude comparison<br />

task committed more errors in <strong>the</strong> addition task two years later. This indicated that in both<br />

cases flawed mastery <strong>of</strong> <strong>the</strong> <strong>place</strong>-<strong>value</strong> concept in first grade was associated with an<br />

increased overall error rate in <strong>the</strong> addition task in third grade. Finally, in contrast to <strong>the</strong><br />

findings <strong>of</strong> Holloway and Ansari (2009) a larger (decade) distance effect in first grade implied<br />

better overall performance in <strong>the</strong> third grade arithmetic task.<br />

Table 3: Regression model predicting <strong>the</strong> overall <strong>number</strong> <strong>of</strong> errors in <strong>the</strong> addition task on <strong>the</strong> basis <strong>of</strong> specific<br />

numerical effects<br />

Predictor B 95% CI b<br />

Change in<br />

R 2 t sig. raw partial<br />

Constant .45 .34 – .56 8.19 < .001<br />

Inversion errors (1 st grade) .30 - .13 – .48 .33 .12 3.47 < .001 .35 .34<br />

Compatibility effect (1 st grade) .09 - .003 – .18 .18 .04 1.93 < .05 ( * ) .24 .20<br />

Distance effect (1 st grade) - .18 - .38 – .01 - .18 .03 1.87 < .05 ( * ) - .17 - .19<br />

CI = Confidence interval; ( * ) = tested one-sided<br />

(iii) Effect approach analyses <strong>of</strong> predictors and criterion variables: Influence <strong>of</strong><br />

specific basic numerical competencies on related effects in mental arithmetic<br />

Finally, taking a step beyond Holloway and Ansari (2009) <strong>the</strong> effect approach was<br />

generalized to both, predictor and criterion variables. That is, we examined in how far mastery<br />

<strong>of</strong> specific basic numerical competencies, in particular <strong>place</strong>-<strong>value</strong> understanding, serves as a<br />

predictor for specific effects in later arithmetic performance. In particular, it was investigated<br />

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