data-exploration

Data Exploration (EDA)

Systematic, evidence-based exploration of a dataset. Produces a structured understanding of data shape, quality, distributions, and relationships.

Iron Law: NO MODELING WITHOUT EXPLORATORY DATA ANALYSIS FIRST

Checklist

You MUST create a task for each of these items and complete them in order:

1. Dataset overview — shape, schema, dtypes, memory usage
2. Target variable analysis — distribution, class balance (if classification)
3. Missing data audit — count, pattern, mechanism (MCAR/MAR/MNAR)
4. Numeric feature analysis — distributions, outliers, skewness
5. Categorical feature analysis — cardinality, value distributions, rare categories
6. Temporal analysis — if datetime columns exist, check trends and gaps
7. Relationship analysis — correlations, mutual information with target
8. Leakage candidate screening — flag suspicious features
9. Data quality score — per-column quality rating
10. EDA summary — key findings, recommended next steps, blockers

Process Flow

digraph eda {
    "Dataset overview" [shape=box];
    "Has target variable?" [shape=diamond];
    "Target variable analysis" [shape=box];
    "Missing data audit" [shape=box];
    "Numeric analysis" [shape=box];
    "Categorical analysis" [shape=box];
    "Has datetime columns?" [shape=diamond];
    "Temporal analysis" [shape=box];
    "Relationship analysis" [shape=box];
    "Leakage screening" [shape=box];
    "Quality score" [shape=box];
    "EDA summary + save report" [shape=doublecircle];

    "Dataset overview" -> "Has target variable?";
    "Has target variable?" -> "Target variable analysis" [label="yes"];
    "Has target variable?" -> "Missing data audit" [label="no"];
    "Target variable analysis" -> "Missing data audit";
    "Missing data audit" -> "Numeric analysis";
    "Numeric analysis" -> "Categorical analysis";
    "Categorical analysis" -> "Has datetime columns?";
    "Has datetime columns?" -> "Temporal analysis" [label="yes"];
    "Has datetime columns?" -> "Relationship analysis" [label="no"];
    "Temporal analysis" -> "Relationship analysis";
    "Relationship analysis" -> "Leakage screening";
    "Leakage screening" -> "Quality score";
    "Quality score" -> "EDA summary + save report";
}