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 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 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:

Zest versus apathy Resolution and fortitude Congruence between desired and achieved goals Self-concept Positive mood tone

The Scales Life Satisfaction Index A (LSIA)

Life Satisfaction Index B (LSIB)

Life Satisfaction Index Z (LSIZ; Wood et al., 1969)

18-item version (Adams, 1969)

8-item version (LSIW; James et al., 1986)

30-item version (Maynard, 1993)

Reliability Generalization Meta-analytic technique Examines average score reliability (e.g.,

Vacha-Haase, 1998)

Examines relationships between study characteristics and score reliability

Sample size Scale length Mean age of sample Standard deviation of age Gender

Mean LSI Standard deviation LSI Language of administration Type of sample

Method – Data Collection PsycINFO literature search

Life 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

Total of 34 samples used

Descriptive Statistics for Sample Characteristics (N=34)Variable M SD RangeSample size 235.53 328.46 20-1571Scale length 17.09 4.21 8-30Mean age 61.79 17.17 20.2-83.3Std dev age 6.89 3.38 3-15.7Proportion female .63 .28 0-1.00Mean LSI 15.56 13.01 3.08-65.5Std dev LSI 3.40 2.34 .52-11.83Lang of admin .78 .42 0-1.00Sample type .26 .51 0-1.00

Results Average Score Reliability

Mean = .79 (SD = .10) Median = .79 Range of .56 (.42 to .98)

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

t tests No difference in score reliability as function of

language of administration or sample type

Discussion Adequate average score reliability for the

LSIFile drawer problem?

No relationship between score reliability and sample characteristics Preliminary evidence for adequate reliability of

scores generated with LSI across various sample characteristics

Limitations?

Future Research & Implications Replication Conceptualization of reliability as property

of scores (e.g., Wilkinson & APA Task Force on Statistical Inference, 1999)

Inclusion of more detailed demographic and reliability information