Title page for ETD etd-04252012-152015

Type of Document Dissertation
Author Nelson, Elizabeth Godbold
URN etd-04252012-152015
Title Hierarchical Linear Modeling versus Visual Analysis of Single Subject Design Data
Degree Doctor of Philosophy (Ph.D.)
Department Psychology
Advisory Committee
Advisor Name Title
Gresham, Frank Committee Chair
Jones, Glenn Committee Member
Kelley, Mary Lou Committee Member
Noell, George Committee Member
Mooney, Paul Dean's Representative
  • small n
  • multilevel modeling
  • single baseline model
  • predictor centering
  • multiple baseline model
  • overdispersion
  • single case
  • n of 1
Date of Defense 2012-04-17
Availability unrestricted
Visual analysis is the “gold standard” for single-subject design data because of a presumed low Type I error rate and consistency across raters. However, research has found it less accurate and reliable than typically assumed. Many statistics have been proposed as aids for visual analysis, but most suffer from limitations either due to methods of investigation or problems inherent to the statistics themselves. Several researchers have proposed the use of Hierarchical Linear Modeling to analyze single-subject data because it can withstand violations of assumptions often present in single-subject data that other statistics cannot. In addition, HLM is similar to the actual data structure of single-subject designs as it allows predictors to be nested within different levels of analysis. Godbold (2008) tested the accuracy of HLM against visual analysis ratings of the same data and found HLM to be a potentially useful statistical aid. The current study rectified the limitations of the 2008 study and extended the applicability of HLM to more types of single-subject designs. HLM was again shown to be a viable statistic across a wide variety of design types including single and multiple baseline designs. Comparisons between two HLM models indicated a longitudinal HLM model was more accurate as compared to visual analysis than a simpler non-longitudinal 2-level model, however, more research is warranted.
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  NelsonDiss.pdf 1.28 Mb 00:05:56 00:03:03 00:02:40 00:01:20 00:00:06
  Nelson_cataloging_abstract.pdf 74.63 Kb 00:00:20 00:00:10 00:00:09 00:00:04 < 00:00:01

Browse All Available ETDs by ( Author | Department )

If you have questions or technical problems, please Contact LSU-ETD Support.