A Reliability Generalization of the Life Satisfaction Index

A Reliability Generalization of the Life Satisfaction Index K. A. Wallace & J. C. Caruso University of Montana Presented at the Annual Meeting of The Gerontological Society of America, November 2002.

Purpose n To examine score reliability for a widely used measure of life satisfaction, the Life Satisfaction Index (LSI; Neugarten et al. , 1961) ¨ Average score reliability ¨ Variation in score reliability as a function of sample characteristics (e. g. , gender; mean age; scale length; etc. )

Developing Ratings of Life Satisfaction n n Crafted to assess well-being using a subjective evaluation of one’s own present and/or past life Part of the Kansas City Study of Adult Life (Neugarten et al. , 1961) ¨ Thematic analysis of measures of adjustment and morale ¨ 5 components of well-being: n n n Zest versus apathy Resolution and fortitude Congruence between desired and achieved goals Self-concept Positive mood tone

The Scales Life Satisfaction Index A (LSIA) n Life Satisfaction Index B (LSIB) n Life Satisfaction Index Z (LSIZ; Wood et al. , 1969) n 18 -item version (Adams, 1969) n 8 -item version (LSIW; James et al. , 1986) n 30 -item version (Maynard, 1993) n

Reliability Generalization Meta-analytic technique n Examines average score reliability (e. g. , n Vacha-Haase, 1998) n Examines relationships between study characteristics and score reliability ü Sample size ü Scale length ü Mean age of sample ü Standard deviation of age ü Gender ü Mean LSI ü Standard deviation LSI ü Language of administration ü Type of sample

Method – Data Collection n Psyc. INFO literature search ¨ Life n satisfaction index and LSI 157 possible articles ¨ 59. 87% no mention of reliability ¨ 9. 56% indicated LSI reliable test, no data ¨ 6. 37% cited reliability from previous work ¨ 3. 18% reported reliability in unusable form ¨. 64% not empirical ¨ 1. 27% could not be obtained ¨ 19. 11% (30) provided usable reliability information n Total of 34 samples used

Descriptive Statistics for Sample Characteristics (N=34) Variable M Sample size 235. 53 Scale length 17. 09 Mean age 61. 79 Std dev age 6. 89 Proportion female. 63 Mean LSI 15. 56 Std dev LSI 3. 40 Lang of admin. 78 Sample type. 26 SD 328. 46 4. 21 17. 17 3. 38. 28 13. 01 2. 34. 42. 51 Range 20 -1571 8 -30 20. 2 -83. 3 3 -15. 7 0 -1. 00 3. 08 -65. 5. 52 -11. 83 0 -1. 00

Results n Average Score Reliability ¨ Mean =. 79 (SD =. 10) ¨ Median =. 79 ¨ Range of. 56 (. 42 to. 98) n Bivariate correlations ¨ Score reliability was not significantly related to: scale length, mean age, standard deviation of age, proportion female, sample size, mean LSI, or standard deviation LSI n t tests ¨ No difference in score reliability as function of language of administration or sample type

Discussion n Adequate average score reliability for the LSI ¨ File n drawer problem? No relationship between score reliability and sample characteristics ¨ Preliminary evidence for adequate reliability of scores generated with LSI across various sample characteristics n Limitations?

Future Research & Implications Replication n Conceptualization of reliability as property of scores (e. g. , Wilkinson & APA Task Force on Statistical n Inference, 1999) n Inclusion of more detailed demographic and reliability information