Table 5.
Comparisons between the excluded and analytic samples
| Analytic Sample | Excluded Sample | t test or Chi-square test | Effect size | |||||
|---|---|---|---|---|---|---|---|---|
| Study variables | N | M (SE)/% | Min/Max | N | M (SE)/% | Min/Max | ||
| Female students | 21,170 | 49% | 0/1 | 3,990 | 48% | 0/1 | 14.04*** | −0.02b |
| Race/ethnicity | 21,170 | — | 1/5 | 3,080 | — | 1/5 | 254.25*** | 0.10b |
| Science identity (9th grade) | 21,080 | 2.31 (0.01) | 1/4 | 4,030 | 2.13 (0.04) | 1/4 | 6.46*** | 0.14a |
| Science identity (11th grade) | 20,780 | 2.48 (0.01) | 1/4 | — | — | 1/4 | — | — |
| Science identity (3 years post-HS) | 20,210 | 2.61 (0.01) | 1/4 | 3,930 | 2.49 (0.05) | 1/4 | 1.35 | 0.05a |
| Science grade (8th grade) | 20,660 | 4.10 (0.02) | 1/5 | 4,000 | 3.65 (0.07) | 1/5 | 19.03*** | 0.42a |
Note. Frequencies displayed are weighted for both samples. aIndicates Cohen’s d was used for measuring effect size among independent sample t-tests for continuous variables. Standard interpretation: small effect: 0.20, moderate effect: 0.50, large effect: 0.80. bIndicates Cramer’s V was used for measuring effect size among Chi-square tests for categorical variables. Standard interpretation: small effect: 0.10, moderate effect: 0.30, large effect: 0.50
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, High School Longitudinal Study of 2009 (HSLS:09), Base Year, First Year Follow-Up, Second Year Follow-Up
*p < 0.05. **p < 0.01. ***p < 0.001