D-score booklet II
Tuning instruments to unity
Preface
1
Introduction
1.1
Previous work on the D-score
1.2
What this volume is about
1.3
Relevance of the work
1.4
Why this booklet?
1.5
Intended audience
2
Data
2.1
Overview of cohorts and instruments
2.2
Cohort descriptions
2.3
Instruments
3
Comparability
3.1
Are instruments connected?
3.2
Bridging instruments by mapping items
3.3
Age profile of item mappings
4
Equate groups
4.1
What is an equate group?
4.2
Concurrent calibration
4.3
Strategy to form and test equate groups
4.4
Parameter estimation with equate groups
4.5
Common latent scale
4.6
Quantifying equate fit
4.6.1
Equate fit
4.6.2
Examples of well fitting equate groups
4.6.3
Examples of equate groups with poor equate fit
4.7
Differential item functioning
4.7.1
Good equate groups without DIF
4.7.2
Poor equate groups with DIF for study
5
Modelling equates
5.1
GCDG data: design and description
5.1.1
Data combination
5.1.2
Equate group formation
5.2
Modelling strategies
5.3
Impact of number of active equate groups
5.4
Age profiles of similar milestones
5.5
Quality of equate groups
5.6
Milestone selection
5.7
Other modelling actions
5.7.1
Instrument fit
5.7.2
Splitting, combining and selecting equate groups
5.8
Item information
5.9
Final model
6
Comparing ability
6.1
Comparing child development across studies
6.2
Precision of the D-score
6.3
Domain coverage
6.3.1
Domain coverage of the scale
6.3.2
Domain-specific D-scores
7
Application I: Tracking a Sustainable Development Goal
7.1
Estimating SDG 4.2.1 indicator from existing data
7.2
Definition
developmentally on track
7.3
Country-level estimates
7.4
Off-track development and stunted growth
8
Application II: Who is on-track?
8.1
What determines who is developmentally on-track?
8.2
Factors that impact child development
9
Discussion
9.1
Potential and limitations of existing data for SDG 4.2.1
9.2
Options for improving health policy
9.3
Suitability of D-score metric
9.4
Suggestions for better measurement
References
D-score booklet II
9.2
Options for improving health policy