A review of the reliability and validity of Likert-type scales for people with intellectual disability.

BACKGROUND Likert-type scales are increasingly being used among people with intellectual disability (ID). These scales offer an efficient method for capturing a wide range of variance in self-reported attitudes and behaviours. This review is an attempt to evaluate the reliability and validity of Likert-type scales in people with ID. METHODS Fifty-one studies reporting response rates, response bias, reliability and validity of Likert-type scales among adolescents and adults with ID were reviewed. RESULTS Low response rates were found among adolescents and adults with moderate to profound ID, when pictorial representations of response alternatives were not employed, and for Likert-type scales with self-descriptive statements. Response bias was evident, particularly among adolescents and adults with moderate to profound ID. Likert-type scales have better reliability and validity among adolescents and adults with borderline IQ or mild ID. Pretests and clarifying questions increase reliability and validity. CONCLUSIONS Likert-type scales should include pictorial representations of response alternatives, a single set of one or two word response descriptors, clarifying questions, and pretests, and are best used with adolescents and adults with borderline IQ to mild ID.

[1]  C. Sigelman,et al.  Asking questions of retarded persons: a comparison of yes-no and either-or formats. , 1981, Applied research in mental retardation.

[2]  R. Luftig.  Assessment of the perceived school loneliness and isolation of mentally retarded and nonretarded students. , 1988, American journal of mental retardation : AJMR.

[3]  R. Cummins,et al.  Validation of the Lifestress Inventory for people with a mild intellectual disability. , 1997, Research in developmental disabilities.

[4]  Jean A. Baker,et al.  Assessment of depression in persons with mental retardation. , 1988, American journal of mental retardation : AJMR.

[5]  A. Loper,et al.  Response bias on a locus of control measure by learning-disabled children , 1983, Journal of abnormal child psychology.

[6]  A. Kazdin.  Converging Themes in Psychotherapy: Trends in Psychodynamic, Humanistic, and Behavioral Practice , 1983 .

[7]  L. Buchan,et al.  Changing Selves: a Grounded Theory Account of Belonging to a Self-advocacy Group for People with Intellectual Disabilities1 , 2004 .

[8]  Y. Lunsky,et al.  Association between perceived social support and strain, and positive and negative outcome for adults with mild intellectual disability. , 2001, Journal of intellectual disability research : JIDR.

[9]  R. Stancliffe.  Assessing opportunities for choice-making: a comparison of self- and staff reports. , 1995, American journal of mental retardation : AJMR.

[10]  H. Prout,et al.  Self-reports of depression by community-based mildly mentally retarded adults. , 1985, American journal of mental deficiency.

[11]  S. Reiss,et al.  Awareness of negative social conditions among mentally retarded, emotionally disturbed outpatients. , 1984, The American journal of psychiatry.

[12]  G. H. Lunney,et al.  USING ANALYSIS OF VARIANCE WITH A DICHOTOMOUS DEPENDENT VARIABLE: AN EMPIRICAL STUDY , 1970 .

[13]  Y. Lunsky.  Depressive symptoms in intellectual disability: does gender play a role? , 2003, Journal of intellectual disability research : JIDR.

[14]  C. Sigelman,et al.  Evaluating alternative techniques of questioning mentally retarded persons. , 1982, American journal of mental deficiency.

[15]  C. Espie,et al.  Glasgow Anxiety Scale for people with an Intellectual Disability (GAS-ID): development and psychometric properties of a new measure for use with people with mild intellectual disability. , 2003, Journal of intellectual disability research : JIDR.

[16]  Y. Lunsky,et al.  Staff and self-reports of health behaviours, somatic complaints, and medications among adults with mild intellectual disability , 2002 .

[17]  Craig J. Russell,et al.  Moderated Regression Analysis and Likert Scales: Too Coarse for Comfort , 1992 .

[18]  W. Lammers,et al.  Depression, Anxiety, and Relevant Cognitions in Persons with Mental Retardation , 2003, Journal of autism and developmental disorders.

[19]  R. Cummins,et al.  The Nature of Stressors Reported by People with an Intellectual Disability , 1999 .

[20]  Richard R. Powell.  Psychometric properties of the Beck Depression Inventory and the Zung Self Rating Depression Scale in adults with mental retardation. , 2003, Mental retardation.

[21]  A. Beck,et al.  An inventory for measuring depression. , 1961, Archives of general psychiatry.

[22]  R. Novaco,et al.  Assessment of anger and aggression in male offenders with developmental disabilities. , 2004, Psychological assessment.

[23]  Lei Chang.  A Psychometric Evaluation of 4-Point and 6-Point Likert-Type Scales in Relation to Reliability and Validity , 1994 .

[24]  R. Callahan.  Thought Field Therapy: Response to our critics and a scrutiny of some old ideas of social science , 2001 .

[25]  A. Kazdin,et al.  Assessment of depression in mentally retarded adults. , 1983, The American journal of psychiatry.

[26]  G. Carlson,et al.  Use of depression rating instruments in developmentally and educationally delayed adolescents. , 1987, Journal of the American Academy of Child and Adolescent Psychiatry.

[27]  J. Rojahn,et al.  A comparison of assessment methods for depression in mental retardation , 1994, Journal of autism and developmental disorders.

[28]  Y. Lunsky,et al.  Reliability of ratings of consumers with mental retardation and their staff on multiple measures of social support. , 1997, American journal of mental retardation : AJMR.

[29]  E. Emerson.  Use of the Strengths and Difficulties Questionnaire to assess the mental health needs of children and adolescents with intellectual disabilities , 2005 .

[30]  J. P. Peter.  Reliability: A Review of Psychometric Basics and Recent Marketing Practices , 1979 .

[31]  W. Finlay,et al.  Acquiescence in interviews with people who have mental retardation. , 2002, Mental retardation.

[32]  W. Maclean,et al.  Perceptions of stress and coping strategies among adults with mild mental retardation: insight into psychological distress. , 2005, American journal of mental retardation : AJMR.

[33]  G. S. Bonham,et al.  Consumer based quality of life assessment: a path model of perceived satisfaction , 2000 .

[34]  R. Cummins,et al.  Conceptualization, measurement, and application of quality of life for persons with intellectual disabilities: report of an international panel of experts. , 2002, Mental retardation.

[35]  W. Lindsay,et al.  The consistency of reports about feelings and emotions from people with intellectual disability. , 2008, Journal of intellectual disability research : JIDR.

[36]  P. Bramston,et al.  Attributional and emotional determinants of aggression in people with mild intellectual disabilities , 1997 .

[37]  C. Sigelman,et al.  Response biases in interviews of individuals with limited mental ability. , 1995, Journal of intellectual disability research : JIDR.

[38]  The Measurement of Stress in People with an Intellectual Disability: A Pilot Study , 1993 .

[39]  G. S. Bonham,et al.  Consumer-based quality of life assessment: the Maryland ask me! Project. , 2004, Mental retardation.

[40]  W. Reynolds,et al.  Depression and learned helplessness in mentally retarded and nonmentally retarded adolescents: an initial investigation. , 1985, Applied research in mental retardation.

[41]  A. Jahoda,et al.  The Glasgow Social Self‐Efficacy Scale—a new scale for measuring social self‐efficacy in people with intellectual disability , 2004 .

[42]  S. Ailey.  Screening Adolescents with Mental Retardation for Depression , 2000, The Journal of school nursing : the official publication of the National Association of School Nurses.

[43]  Eli P. Cox,et al.  The optimal number of response alternatives for a scale: A review. , 1980 .

[44]  P. Bramston,et al.  The assessment of emotional distress experienced by people with an intellectual disability: a study of different methodologies. , 2000, Research in developmental disabilities.

[45]  S. Kellett,et al.  Measuring interpersonal problems in people with mental retardation. , 2005, American journal of mental retardation : AJMR.

[46]  Ralph Kober,et al.  Factor stability of the Schalock and Keith (1993) Quality of Life Questionnaire. , 2002, Mental retardation.

[47]  P. Birleson.  The validity of depressive disorder in childhood and the development of a self-rating scale: a research report. , 1981, Journal of child psychology and psychiatry, and allied disciplines.

[48]  D. Hodge,et al.  Phrase Completions: An Alternative to Likert Scales. , 2003 .

[49]  S. Sawilowsky,et al.  Analysis of Likert scale data in disability and medical rehabilitation research. , 1998 .

[50]  E. Emerson,et al.  The development of a self-report measure to assess the location and intensity of pain in people with intellectual disabilities. , 1998, Journal of intellectual disability research : JIDR.

[51]  P. Bobko,et al.  Moderated regression analysis and Likert scales: too coarse for comfort. , 1992, The Journal of applied psychology.

[52]  John P. Robinson,et al.  CHAPTER 1 – Criteria for Scale Selection and Evaluation , 1991 .

[53]  B. Benson,et al.  Anger, depression and self-concept in adults with mental retardation. , 2008, Journal of intellectual disability research : JIDR.

[54]  Charles Antaki,et al.  Interviewing Persons with a Learning Disability: How Setting Lower Standards May Inflate Well-Being Scores , 1999 .

[55]  C. Sigelman,et al.  Pictures as an Aide in Questioning Mentally Retarded Persons. , 1986 .

[56]  C. Böhmer,et al.  Prevalence, diagnosis and treatment of gastro-oesophageal reflux disease in institutionalised persons with an intellectual disability , 2002 .

[57]  A. Kazdin,et al.  An inventory to assess psychopathology of mentally retarded adults. , 1985, American journal of mental deficiency.

[58]  S. Kellett,et al.  Utility of the Brief Symptom Inventory in the Assessment of Psychological Distress , 2003 .

[59]  D. Helm.  The measurement of happiness. , 2000, American journal of mental retardation : AJMR.

[60]  P. Bramston,et al.  Measuring perceived stress in people with intellectual disabilities: The development of a new scale , 1994 .

[61]  J. Matson,et al.  The relationship of depression to social skills and intellectual functioning in mentally retarded adults. , 2008, Journal of mental deficiency research.

[62]  J. L. Winer,et al.  The Responsiveness of Mentally Retarded Persons to Questions , 1982 .

[63]  D. Dagnan,et al.  Social comparison, self-esteem and depression in people with intellectual disability. , 2001, Journal of intellectual disability research : JIDR.

[64]  J. Jacoby,et al.  Is There an Optimal Number of Alternatives for Likert Scale Items? Study I: Reliability and Validity , 1971 .

[65]  J. Matson,et al.  Assessment of depression in mentally retarded adolescents. , 1993, Research in developmental disabilities.

[66]  W. Reynolds.  The Utility of Multiple-Choice Test Formats With Mildly Retarded Adolescents , 1979 .

[67]  J. Chadsey-Rusch,et al.  Assessing the loneliness of workers with mental retardation. , 1992, Mental retardation.

[68]  P. Brovedani,et al.  Assessment of Anxiety and Depression in Adolescents with Mental Retardation , 2002, Child psychiatry and human development.

[69]  P. Linn,et al.  Implications for Research and Practice , 2003 .

[70]  R. Stancliffe.  Proxy respondents and quality of life , 2000 .

[71]  A. Nezu,et al.  Depression in adults with mild mental retardation: Are cognitive variables involved? , 1995, Cognitive Therapy and Research.

[72]  P. Schloss.  Verbal interaction patterns of depressed and non-depressed institutionalized mentally retarded adults. , 1982, Applied research in mental retardation.

[73]  S Flamer,et al.  Assessment of the Multitrait-Multimethod Matrix Validity of Likert Scales Via Confirmatory Factor Analysis. , 1983, Multivariate behavioral research.

[74]  Eli P. Cox,et al.  The Optimal Number of Response Alternatives for a Scale: A Review , 1980 .

[75]  L. Heal,et al.  The Lifestyle Satisfaction Scale (LSS): assessing individuals' satisfaction with residence, community setting, and associated services. , 1985, Applied research in mental retardation.

[76]  R. Cummins,et al.  An Italian-Australian comparison of quality of life among people with intellectual disability living in the community. , 1999, Journal of intellectual disability research : JIDR.

[77]  C. Sigelman,et al.  Surveying mentally retarded persons: responsiveness and response validity in three samples. , 1980, American journal of mental deficiency.

[78]  R. Cummins,et al.  An Initial Evaluation of the Comprehensive Quality of Life Scale‐‐Intellectual Disability , 1997 .

[79]  R. Cummins,et al.  Adaptive Behaviour in Children and Adolescents With and Without an Intellectual Disability: Relationships with Fear and Anxiety , 1995, Behaviour Change.

[80]  P. Bramston,et al.  Disability and stress: a study in perspectives , 2001 .