Structured pipeline for statistical analysis deliverables — SPSS, R, Python. Covers reliability, chi-square, correlation, regression, assumption checking, and client-ready reporting.
Purpose: Structured pipeline for statistical analysis deliverables. Prevents assumption violations, missed effect sizes, and uninterpretable output. Origin: Created ahead of Assignment 19 (SPSS, Siva, $250, deadline Mar 8). No protocol coverage existed for this domain.
[!IMPORTANT] Every statistical test has assumptions. Violating them invalidates results. Check BEFORE running.
| Test Family | Assumptions | Check Method |
|---|---|---|
| Reliability (Cronbach's α) | Unidimensionality, interval/ratio data, ≥3 items per scale | Factor analysis / item-total correlations |
| Chi-Square (χ²) | Independence, expected frequency ≥ 5 in 80%+ cells, categorical variables | Expected frequency table |
| Pearson Correlation | Linearity, normality (both vars), no significant outliers, interval/ratio | Scatter plot, Shapiro-Wilk |
| Spearman Correlation | Monotonic relationship, ordinal or non-normal interval | Scatter plot (monotonic check) |
| Multiple Regression | Linearity, independence (Durbin-Watson), homoscedasticity, normality of residuals, no multicollinearity (VIF < 10) | Residual plots, VIF table, Durbin-Watson |
| Independent t-test | Normality, homogeneity of variance (Levene's), interval/ratio DV | Shapiro-Wilk, Levene's |
| One-way ANOVA | Normality, homogeneity (Levene's), independence, interval/ratio DV | Same as t-test + post-hoc if significant |
For each test in the scope:
For each test result, produce a 3-part interpretation:
| Effect Size | Small | Medium | Large |
|---|---|---|---|
| Cohen's d | 0.2 | 0.5 | 0.8 |
| r | 0.1 | 0.3 | 0.5 |
| R² | 0.01 | 0.09 | 0.25 |
| η² | 0.01 | 0.06 | 0.14 |
| Cramér's V (df=1) | 0.1 | 0.3 | 0.5 |
| Cronbach's α | < 0.6 poor | 0.7–0.8 acceptable | > 0.9 excellent |
Structure the output document:
1. Introduction (research context, variables, hypotheses)
2. Methodology (sample, measures, statistical tests used)
3. Results
3.1 Reliability Analysis
3.2 Chi-Square Tests
3.3 Correlation Analysis
3.4 Regression Analysis
4. Discussion (interpret findings, connect to research questions)
5. Limitations
6. References
Appendix: SPSS Output Tables (screenshots or formatted tables)
| Component | Count | Details |
|---|---|---|
| Reliability (Cronbach's α) | 5 | One per scale/construct |
| Chi-Square (χ²) | 4 | Independence tests (demographic × outcome) |
| Correlation | 4 | Bivariate (IV-DV pairs) |
| Regression | 1 | Multiple regression (4 IVs → 1 DV) |
| Total tests | 14 | |
| Topic | Safety Training in SG Construction | |
| N | 185 survey responses | |
| IVs | 4 (to be identified from data) | |
| DV | 1 (to be identified from data) |