Reliability and validity of the Testwell: Wellness Inventory -- High School edition.

Abstract

The purpose of this research was to obtain reliability and validity evidence for the Testwell: Wellness Inventory--High School Edition (TWI(HS)). The TWI(HS) is a 100 item inventory divided into 10 subscales of 10 items each. Subjects for this research were 437 9th- and 10th-grade students attending five Tennessee public high schools. The subjects were either enrolled in Lifetime Wellness Curriculum classes or had yet to take the class.

Four research questions were posed for this study: (1) What is the internal consistency of the Testwell: Wellness Inventory--High School Edition in 9th- and 10th-grade males and females? (2) What is the 12-week test/retest reliability of the Testwell: Wellness Inventory-High School Edition in 9th- and 10th-grade males and females? (3) Is the internal structure of wellness attitudes comprised of 10 domains, or factors, as hypothesized by the authors of the Testwell: Wellness Inventory--High School Edition? (4) Do the scores on Testwell: Wellness Inventory--High School Edition measure changes in wellness attitudes?

Data were analyzed for internal consistency using a two-way ANOVA model for each of the 10 subscales and the total test. Cronbach's alphas ranged from 0.67 to 0.89 for the 10 subscales and 0.96 for the total test. To determine test/retest reliability an intraclass correlation coefficient was calculated using a one-way ANOVA model for each subscale and the total test. An F-test was conducted to determine if significant differences existed between the mean pre- and posttest scores for each subscale and the total test, and the Spearman-Brown Prophecy formula was used to adjust intraclass correlation coefficients to estimate reliability for a single trial. No mean difference (p {dollar} greater than {dollar}.05) was found for the total test and for 9 of the 10 subscales. One subscale (Self-Care) had a significant ({dollar}p less than .05{dollar}) mean increase of 1.5. When correlation coefficients were adjusted for a single trial, the adjusted correlation coefficients ranged from 0.63 to 0.82 for the 10 subscales and was 0.87 for the total test.

Exploratory factor analysis was used to force a 10-factor structure on the data. This analysis did not produce a clear simple factor-loading pattern to indicate that the TWI(HS) is composed of 10 factors as hypothesized by the authors.

The scores of the subjects enrolled in the Lifetime Wellness classes were analyzed to measure changes in wellness attitudes. Scores for each subscale and the total test were analyzed using repeated measures t-tests to determine if scores changed from the pre- to the posttest. The mean was significantly (p {dollar} less than {dollar}.05) higher for only three of the ten subscales. These subscales were Physical Fitness and Nutrition, Environmental Wellness, and Social Awareness. There was no significant mean difference for the other seven subscales or the total test.

The conclusions of the research were that the TWI(HS) may not be a reliable or valid instrument with which to measure wellness attitudes and behaviors of 9th- and 10th-grade students.