VITA

RATNA NANDAKUMAR

Address:

Office: 
University of Delaware    
School of Education        
Voice Mail: 302-831-1635
Email: nandakum@udel.edu

Home:
6 Woodshaw Road
Newark, DE 19711
213 Willard Hall          
Newark, DE 19711

Education

Ph.D. (Education), 1987
University of Illinois at Urbana-Champaign
Major Area: Educational Statistics and Psychometrics.

A.M. (Statistics), 1976
University of Illinois at Urbana-Champaign

M.Sc. (Statistics), 1974
Bangalore University, India

B.Sc. (Honors) (Mathematics), 1972
Bangalore University, India

Professional Positions

Professor. School of Education, University of Delaware. 1999 -

Associate Professor. Department of Educational Studies, University of Delaware.  1993 - 1999.

Assistant Professor. Department of Educational Studies, University of Delaware. 1987 - 1993.

Graduate Research Assistant. Department of Statistics, University of  Illinois at Urbana-Champaign. 1984 - 1987.

Graduate Research Assistant. Institute for Child Behavior and Development, University of Illinois at Urbana-Champaign.  1982 - 1985.

Graduate Teaching Assistant. Department of Educational Psychology, University of Illinois at Urbana-Champaign. 1984.


Refereed Publications

Yu, F., & Nandakumar, R. (2001). Poly-Detect for quantifying the degree of multidimensionality. Journal of Educational Measurement, 38, 99-120.

Nandakumar, R. & Roussos, L. (in press). Evaluation of  CATSIB procedure in pretest setting.  Journal of Educational and Behavioral Statistics.

Roussos, L. A., Nandakumar, R., & Cwikla-Banks, J. (in press).  Theoretical formula for statistical bias in CATSIB DIF estimator due to discretization of the ability scale.  LSAC Computerized Testing

Report.  Newtown, PA:  Law School Admission Council.

Nandakumar, R., & Roussos, L. A. (in press).  CATSIB: A modified SIBTEST procedure to detect differential item functioning in computerized adaptive tests.  LSAC  Computerized Testing Report, 97-11.  Newtown, PA: Law School Admission Council.

Nandakumar, R., Yu, F., Li, H., & Stout, W. (1998). Assessing unidimensionality of polytomous data. Applied Psychological Measurement, 22, 99-115.

Stout, W., Li, H., Nandakumar, R., & Bolt, D. (1997). MULTISIB - A procedure to investigate DIF when a test is intentionally multidimensional. Applied Psychological Measurement, 21, 195-213.

Nandakumar, R., & Yu, F. (1996). Empirical validation of Dimtest on nonnormal ability distributions.  Journal of Educational Measurement, 33, 355-368. 

Stout, W., Nandakumar, R., & Habing, B. (1996). Analysis of latent dimensionality of  dichotomously and polytomously scored test data. Behavior Metrika, 23, 37-65.

Golinkoff, R. M., Jacquet, R. C., Hirsh-Pasek, K., & Nandakumar, R. (1996). Lexical principles may underlie the learning of verbs. Child Development, 67, 3101-3119.

Nandakumar, R. (1994).  Assessing latent trait unidimensionality of a  set of items - -comparison of different approaches.  Journal of Educational Measurement, 31, 1-18.

Nandakumar, R. (1993). Simultaneous DIF amplification and cancellation:  Shealy-Stout's test for DIF. Journal of Educational Measurement, 30,  293-311.

Nandakumar, R. (1993). A FORTRAN  77 program for detecting differential item function through Mantel-Haenszel Statistics.  Educational and Psychological Measurement, 53, 679-684.

Nandakumar, R., & Stout, W. (1993). Refinements of Stout's procedure for assessing latent trait unidimensionality.  Journal of Educational  Statistics, 18, 41-68.

Nandakumar, R. (1993). A FORTRAN program for assessing essential  unidimensionality data using Holland and Rosenbaum's methodology. Multivariate Behavioral Research,  28, 63-66.

Nandakumar, R. (1993). Assessing dimensionality of real data. Applied Psychological Measurement, 17, 29-38.

Nandakumar, R., Glutting, J, & Oakland, T. (1993). Mantel-Haenszel methodology for detecting item bias: An introduction and example using the Guide to the Assessment of Test Session Behavior.  Journal of Psychoeducational Assessment, 11, 108-119.

Stout, W.F., Nandakumar, R., Junker, B., Chang, H., & Steidinger, D. (1992). DIMTEST: A FORTRAN program for assessing dimensionality of binary item  responses.  Applied Psychological Measurement, 16, 236.

Nandakumar, R. (1991). Traditional dimensionality vs. essential  dimensionality.  Journal of Educational Measurement, 28,  99-117.

Conference Proceedings and Technical Reports

Nandakumar, R., Cwikla, J., and Roussos, L. (2000). Kernel-Smoothed DIF Detection Procedure for Computerized Adaptive Tests. LSAC Computerized Testing Report.  Newtown, PA:  Law School Admission Council.

Nandakumar, R. (1993). Simultaneous item bias cancellation and amplification:  Shealy-Stout test for bias.  In Steyer, R., & Wender, K.F., (Eds),  Psychometric methodology: Proceedings of the 7th European Meeting of the Psychometric Society in Trier (pp. 355-360).  Stuttgart:   Gustav Fischer Verlag.

Nandakumar, R., & Stout, W. (1992a). Refinements of Stout's procedure for assessing latent trait unidimensionality.  Research Report 1992-1. Urbana, IL: Office of Naval Research Technical Report.

Nandakumar, R. (1992b). Assessing dimensionality of real data. Research Report 1992-2. Urbana, IL: Office of Naval Research Technical Report.

Nandakumar, R. (1992c). Assessing latent trait unidimensionality of a set of items-Comparison of different approaches. Research Report 1992-3. Urbana, IL: Office of Naval Research Technical Report. 

Nandakumar, R. (1992d). Simultaneous item bias amplification and cancellation: Shealy-Stout's test for DIF. Research Report 1992-4. Urbana, IL: Office of Naval Research Technical Report.

Book Review

Nandakumar, R. (1991). [Review of A handbook of introductory statistical methods].  Journal of Educational Statistics, 16, 373-376.

Recent Conference Presentations

Nandakumar, R., Hotchkiss, L., & Roberts, J. (2002, June). Dimensionality assessment of attitudinal data. Paper presented at the annual meeting of the Psychometric Society, University of North Carolina, Chapel Hill.

The conference session Chair: Instrument Development. At the annual meeting of the Psychometric Society, The University of North Carolina at Chapel Hill. Chapel Hill, North Carolina (June, 2002).

Nandakumar, R., Hotchkiss, L., & Roberts, J. (2002, April). Attitudinal Data: Dimensionality and Start Values for Estimating Item Parameters. Paper presented at the annual meeting of the American Educational Research Association, New Orleans.

Finch, H., Habing, B., Roberts, J., and Nandakumar, R. (April, 2002). A Q3 statistic for unfolding item response theory models. Paper presented at the annual meeting of the American Educational Research Association, New Orleans.

Oh, H., Nandakumar, R., Glutting, J. and Zhang, L. (June, 2002). DIF in  mathematics in on Delaware student testing program for 3rd grade: Comparison of Mantel-Haenszel, logistic regression, and SIBTEST procedures. Paper presented at the annual meeting of the American Educational Research Association, New Orleans.

The conference session Discussant: Assessing multi-dimensionality: Measure twice; cut once. At the annual meeting of the American Educational Research Association, New Orleans (April, 2002).

Nandakumar, R. (2001, November). Yoga in Education. Session Chair at the 12th International Conference on Frontiers of Yoga Research and Applications, Prashanti Kutiram, Bangalore, India.

Nandakumar, R., Roberts, J. (2001, June). Dimensionality Structure of Attitudinal Data. Paper presented at the annual meeting of the Psychometric Society, Valley Forge Conference Center, King of Prussia, PA.

Nandakumar, R., Roussos, L., & Cwikla, J. (2000, April). DIF assessment of CAT data: Kernel-smoothed CATSIB. Paper presented at the annual meeting of the National Council on Measurement in Education, New Orleans.

Yu, Feng., &  Nandakumar, R. (2000, April). Pretest item calibration under CAT environment. Paper presented at the annual meeting of the National Council on Measurement in Education, New Orleans.

Roussos, R., Nandakumar, R., and Cwikla, J. (1999, June). Matching variable for CATSIB: Number of intervals and scaling. Paper presented at the annual meeting of the Psychometric Society, Lawrence, Kansas.

Roussos, R., Nandakumar, R., and Cwikla, J. (1999, April). Kernel-smooth CATSIB DIF detection. Paper presented at the annual meeting of the American Educational Research Association, Montreal, Canada.

Nandakumar, R., Roussos, L. A., and Stout, W. (1999, April). Development of a unidimensional DIF-free matching subtest for DIF assessment. Paper presented at the annual meeting of the National Council on Measurement in Education, Montreal, Canada.

Roussos, L. and Nandakumar, R. (1998, June). Kernel-Smoothed CATSIB. Paper presented at the annual meeting of the Psychometric Society, Champaign-Urbana, IL.

Roussos, L. and Nandakumar, R. (1997, June). Using a modified SIBTEST procedure to detect CATDIF. Paper presented at the annual meeting of the Psychometric Society, Gatlinburg, Tennessee.

Nandakumar, R., and Roussos, L. (1997, March). Validation of CATSIB to investigate DIF of  computerized adaptive test data. Paper presented at the annual meeting of the American Educational Research Association, Chicago, IL.

Yu, F., and Nandakumar, R. (1997, March). Validation of Poly-Detect procedure to assess the degree of multidimensionality of polytomous data. Paper presented at the annual meeting of the American Educational Research Association, Chicago, IL.

Yu, F., and Nandakumar, R. (1997, March). The impact of second ability dimension on the unidimensional BILOG estimation of item and ability parameters. Paper presented at the annual meeting of the National Council on Measurement in Education, Chicago, IL.

Ross, L., Clauser, B., and Nandakumar, R. (1997, March). A simulation study of the use of Mantel-Haenszel and Logistic Regression procedures for assessing DIF in a computerized adaptive testing environment. Paper presented at the annual meeting of the National Council on Measurement in Education, Chicago, IL.

Nandakumar, R., and Yu, F. (1996, June). DETECT for  polytomous item response data. Paper presented at the annual meeting of the Psychometric Society, Banff Center for Conferences, Banff, Alberta, Canada.

Ross, L., Clauser, B., and Nandakumar, R. (1996, April). Assessing differential impact: Effects of DIF screening on examinee performance, test characteristics, and test dimensionality. Paper presented at the annual meeting of the National Council on Measurement in Education, New York.

Nandakumar, R., and Yu, F. (1995, June). Validation of  Poly-Dimtest to assess unidimensionality of polytomous data. Paper presented at the annual meeting of the Psychometric Society, University of Minnesota, Minneapolis.

Nandakumar, R. (1995, June). Using small groups to improve instruction. Paper presented at the third annual teaching retreat, Wakonse-East, Sandy Hill Conference Center, MD. Sponsored by the Center for Teaching Effectiveness, University of Delaware.

Invited Addresses, Workshops and Conferences

Nandakumar, R. (2001, November). Statistical assessment of item bias (DIF) in the context of computerized adaptive testing. Invited talk presented at Indian Statistical  Institute, Bangalore, India.

Nandakumar, R. (2001, fall). Seminar course in Psychometrics. Department of Statistics, Bangalore University, Bangalore, India.

Nandakumar, R. (2001, fall). Seminar Series in Educational and Psychological Measurement. Department of Psychology, Bangalore University, Bangalore, India.

Nandakumar, R. (2001, August). Testing and Item Response Theory. Invited talk given at the Birla Institute of Technology, Pilani, India.

Nandakumar, R. & Davis, J. (1998, February). Constructing Better Tests.  Workshop presented at the Center for Teaching Effectiveness, University of Delaware.

Nandakumar, R. (1997, March). Assessing multidimensionality of polytomous data. Invited talk presented at the symposium on “Integrating test design with psychometric theory: Using a nonparametric toolbox for assessing dimensionality” at the annual meeting of the National Council on Measurement in Education, Chicago, IL.

Nandakumar, R. (1996, December). Robustness of item and ability parameter estimates under the violation of unidimensionality assumption. Invited talk presented at the Law School Admission Council, Psychometrics Research Group, December 12, 1996, Newtown, PA.

Yu, F. & Nandakumar, R. (1996, April). Dimensionality of NEAP Data. Invited paper presented at the annual meeting of the American Educational Research Association, New York.

Nandakumar, R. (1995, May). SIBTEST: A statistical test for assessing DIF, and its applications for assessing DIF in various situations. Invited talk presented at the National Board of Medical Examiners, Philadelphia.

Nandakumar, R. (1995, April). Application of SIBTEST in dealing with issues of DIF in the context of multidimensional data. Invited talk presented at the symposium "Perspectives on Differential Item Functioning Analysis in the Context of Multidimensional Test Data" at the annual meeting of the National Council on Measurement in Education.

Nandakumar, R. (1993, November). Item Response Theory.  Invited talk  presented at the American Statistical Association-Delaware Chapter,  Newark, Delaware.

Nandakumar, R. (1992, April). Statistical Analysis of multidimensionality for real data sets. Invited talk presented at the annual American Educational  Research Association meeting, San Francisco, California.

Nandakumar, R. (1992, March).  Assessing the essential dimensionality of the latest space underlying binary item responses. Invited talk  presented in the Operations Research Seminar Series, University of Delaware.

Nandakumar, R. (1992, February).  Assessing  essential dimensionality of latent space underlying binary item responses. Invited talk presented in the Quantitative Methods Group Seminar Series, University of Delaware.

Nandakumar, R. (1988, July). Unidimensionality and Stout's procedure for assessing unidimensionality.  Invited colloquium presented at the Division of Psychometry, Indian Statistical Institute, Calcutta, India.

Grants

Nandakumar, R. Title: Dimensionality Assessment of Attitudinal Data. Spencer Foundation, 2002-03. Amount: $34,450.

Nandakumar, R. Title: Kernel-smoothed DIF detection procedure for computerized adaptive tests. Law School Admission Council. 1998-2000. Amount: $38,502.00.

Nandakumar, R. Title: Further modifications of DIMTEST for assessing unidimensionality. Office of Naval Research Cognitive Science Research Grant.  1990-1992. Amount: $8,000.

Nandakumar, R. Title: Development of software for Mantel-Haenszel DIF statistic. Class of 1949 Summer Research Grant, University of Delaware. 1990. Amount: $1,000.

Nandakumar, R. Title: Validation and comparison of Stout's procedure for assessing unidimensionality. General University Grant, University of Delaware. 1987-1988. Amount: $5,000.

Nandakumar, R. Dissertation Research Grant. University of Illinois at Urbana-Champaign. 1985-1986. Amount: $1,000.

Teaching

Graduate Courses Taught:

Advanced Educational Measurement

Educational Measurement Theory

Multivariate Data Analysis in Education

Statistical Inference

Elementary Statistics

Educational Research Procedures

Undergraduate Course Taught:

            Measurement Theory and Techniques for Classroom Teachers

Professional Activities

Editorial Board:

Journal of  Educational Measurement.

Reviewer:

Applied Measurement in Education,  Applied Psychological Measurement, Multivariate Behavioral Research, Educational Measurement: Issues and Practice, Psychological Methods, Psychometrika, American Educational Research Association, Division D, National Council on Measurement in Education.

Committee Chair:

Training and Professional Development Committee of National Council on Measurement in Education (1999-01).

Conference Session Chair and Discussant:

American Educational Research Association, National Council on Measurement in Education,

Psychometric Society.

Grant Reviewer:

National Board of Medical Examiners' Medical Education Research Fund (1995-1996).

Delaware State Department of Education:

Technical Advisor, Assessment and Accountability        Branch (1994-).

            Member, Technical Advisory Committee (1998-99).

Member, Validation Panel of Praxis II Subject Assessment (1994-96).

Consultant, Examination of alternative tests to PPST to recruit teachers (1987-88).

University Activities

School of Education

Coordinator, MSE Doctoral Program (1991-94; 1998-00).

Chair, School of Education Promotion and Tenure Committee (1999-2000).

College of Human Resources, Education, and Public Policy

Member, International Teacher Education Committee (1996-97).

Member, Promotion and Tenure Committee (1997-98).

University

1.      Member, 2000 Eugene duPont Scholars Selection Committee (1999-01).

2.      Member, American Association of University Professors Steering Committee (1995-1999).

3.      Member at Large, American Association of University Professors. Executive Council (1999-01).

4.      Member, Center for Teaching Effectiveness, Third Annual Wakonse-East Teaching Retreat Planning Committee (1994-95).

5.      Member, Senate Committee on Research (1996-98).

6.      Faculty Advisor, Indian Students Association (1997-99).

7.      Faculty Advisor, University of Delaware Yoga Club (1996-98).

Membership in Professional Societies

American Educational Research Association

National Council on Measurement in Education

Psychometric Society

American Statistical Association-Delaware Chapter