Interview - Not a good process to recruit

Interviews are being conducted to recruit workers for organisation. But it is not actually a good selection process for that. The actual ability of a person cant be determined in the minutes of meeting. More over it is filtered by the percentage one scores. The percentage depends on how one studies and not on the knowledge. A knowledged person may not study for hours and his percentage will be low but a less knowledged person who studies for hours may score good percentage. The later may be rewarded for his hardwork but the knowledged one should not be suppressed. The usual selection process consisits of a written Exam, a group discussion, a technical round, a psycometric test and finally a HR round. The written exam may contain both technical and apptitude questions. The Group discussion may be replaced by JAM (Just a minute). The technical questions will be from the core subjects. The psycometric test is to check the attitude and the HR round is to ensure weather the person suits the organisation to achieve the long term goal.Most of the recruiters think all these process can select the best canditates for the organisation but is a misbelief.