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Asia-Pacific Science Education

Table 1 Sequence of Rasch measurement models estimated for each data set

From: Is it harder to know or to reason? Analyzing two-tier science assessment items using the Rasch measurement model

Model

Dimensions

Number

Terms

Data Set 1 (LPDI)

Data Set 2 (CTSR)

1

None

Unidimensional

(17 parameters)

Unidimensional

(25 parameters)

2

Tier

Two dimensions:

Tier 1; Tier 2

(19 parameters)

Two dimensions:

Tier 1;Tier 2

(27 parameters)

3

Content

Two dimensions:

Light Propagation; Visibility

(19 parameters)

Four dimensions:

Control of Variables; Combinatorial Reasoning; Proportional Reasoning; Probabilistic Reasoning

(34 parameters)

4

Tier × Content

Four dimensions:

Tier 1; Tier 2

×

Light Propagation; Visibility

(26 parameters)

Eight dimension:

Tier 1; Tier 2

×

Control of Variables; Combinatorial Reasoning; Proportional Reasoning; Probabilistic Reasoning

(60 parameters)

  1. Note. All models were estimated as dichotomous Rasch models. The Model 4 for both data sets was estimated as between-item models, meaning that an item was assigned to a combination of tier and content. The parameters listed indicate the complexity of the statistical model by representing the combination of dimensions and items in that model
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