PIRLS 2016 Results
The PIRLS international achievement scales were developed based on item response theory and population models using plausible values, with each student respondent being assigned 5 plausible values on each of the achievement scales.
Scale scores range from 0 to 1000.
Each international scale was established by PIRLS 2001 to have a midpoint of 500 located at the mean of the combined achievement distribution across all countries and 100 scale score points corresponding to one standard deviation of the combined distribution.
In order to measure trends over time, the results of all subsequent PIRLS assessments (2006, 2011, and 2016) were converted to this metric.
LIST OF ACHIEVEMENT SCALES
- Overall achievement (Reading)
- Purposes for Reading
- Literary Experience
- Acquire and Use Information
- Processes of Comprehension
- Retrieving and Straightforward Inferencing
- Interpreting, Integrating, and Evaluating
- ePIRLS Online Informational Reading
Overall achievement results were reported in terms of the percentages of students reaching the following four international benchmarks:
- Advanced International Benchmark (625)
- High International Benchmark (550)
- Intermediate International Benchmark (475)
- Low International Benchmark (400)
The descriptions of the competencies of students reaching each of these benchmarks were determined by means of a scale-anchoring process.
PIRLS 2016 created a variety of background questionnaire scales to report the context questionnaire data.
Scales were calculated using item response theory (IRT), specifically a Rasch partial credit model.
In addition, categorical variables were created using these scales by classifying respondents into one of three groups: High, Middle, and Low. Cut-off points for categorization were determined on a scale-by-scale basis.
Forthcoming in December 2017