Randomization is done to reduce ?

Selection bias Types of bias * Selection bias is a distoion in the estimate of association between risk factor and disease that results from how the subjects are selected for the study. * Information bias is due to systematic measurement error or misclassification of subjects on one or more variables, either risk factor or disease status. * Confounding -results when the risk factor being studied is so mixed up with other possible risk factors that its single effect is very difficult to distinguish. Ref: Park 24th edition