Actually i am a beginner and i am not familar with preprocessing,i fill missing values with mean and median then i apply PCA to the dataset and then i apply ML models like logistic regression and KNN but score not increases it is stops at 62 any suggestions to improve my model
2. fill in the missing value
4. features selection
Try using Gradient Boosting Algorithms like catboost, xgboost,lightgbm e.t.c
i tried using both catboost and xgboost but got a lower score. I also got a lower score when i used mean and median for filling the missing values.