Assess ability to design a rigorous experimental protocol and statistical analysis plan to quantify how microplastic particle size and polymer type influence soil microbial community composition and function across varied moisture regimes. Include clear hypotheses, treatment selection (particle sizes, polymer classes, moisture treatments), controls, replication and randomization strategy, sampling schedule, molecular and functional assays (e.g., 16S/ITS or metagenomics, respiration, enzyme activities, nutrient cycling rates), soil physicochemical measurements, contamination control, power/sample-size considerations, data preprocessing, multivariate and univariate statistical models (e.g., diversity metrics, PERMANOVA, mixed-effects models, interaction terms), differential abundance testing, visualization, and interpretation of limitations and confounders.