IRT scoring procedures for TIMSS data.

In large-scale international assessment programs, results for mathematics proficiency are typically reported for jurisdictions such as provinces or countries. An overall score is provided along with subscores based on content subdomains defined in the test specifications. In this paper, an alternative method for obtaining is described, where the empirical subscores are based on an exploratory item response theory (IRT) factor solution.

Limited microdiscectomy for lumbar disk herniation: a retrospective long-term outcome analysis.

Objective And Summary Of Background Data: Surgical treatment of lumbar disk herniation is traditionally accomplished by removal of the extruded fragment as well as an aggressive decompression of the disk space. This retrospective study evaluates the long-term results of limited discectomy, otherwise known as fragmentectomy, for lumbar disk herniation using a minimally invasive technique. Although there are ample studies in literature regarding short-term outcome after limited microdiscectomy, there is a paucity of literature for long-term outcomes after fragmentectomy.