Tense marking at the point of school entry, that is, kindergarten, has been hypothesized to follow a bimodal distribution. Under this hypothesis, it is predicted that most children exhibit tense marking skills at or near the upper end of proficiency whereas some children demonstrate notably reduced proficiency. Due to this separation of skill level, kindergarten tense marking is considered a clinical marker for language impairment. The purpose of this study was to test the validity of a bimodal distribution of tense marking in a population-based sample of kindergarten students. The Test of Early Grammatical Impairment (TEGI) Screening Test was administered to three-quarters of the kindergarten students attending a school district of Mainstream American English speakers. Results revealed a distribution of TEGI Screening Test Scores that deviated significantly from normality. Cluster analysis indicated a best-fitting two-cluster solution that, upon inspection, generally aligned with bimodal-distribution expectations for typical and language-impaired classification prevalence rates and threshold values. Cross validation of child cluster membership to a reference standard for a subsample of participants offered further, albeit preliminary, evidence in support of the discriminant validity of assessing tense marking for the purpose of identifying language impairment in the general kindergarten population.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-03282016-164932 |
| Date | 30 March 2016 |
| Creators | Weiler, Brian Kenneth |
| Contributors | Megan Saylor, James Bodfish, Stephen Camarata, C. Melanie Schuele |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-03282016-164932/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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