You will find below a summary of Jacob Joseph post.
Original article is here:
Unless the nature of missing data is ‘Missing completely at random’, the best avoidable method in many cases is deletion.
a) Popular averaging techniques. Mean, median and mode are the most popular averaging techniques, which are used to infer missing values. Approaches ranging from global average for the variable to averages based on groups are usually considered.
Imputation of missing values is a tricky subject and unless the missing data is not observed completely at random, imputing such missing values by a Predictive Model is highly desirable since it can lead to better insights and overall increase in performance of your predictive models
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