Following are some drawbacks of observation method:
Observation method is not suitable for studying life histories or private behaviour.
2. Costly Method
Observation method is costly method of collecting data. It needs the services of trained and experienced observers and the work of observation may continue for a long time.
3. Not Suitable for Behavioural Studies
It cannot be used effectively to observe behavioural qualities like attitude, likes, motivation, etc. For example, it is possible to observe which brand of soap a consumer is buying but it is difficult to find out why he is buying a particular brand. In short, only actions can be observed and not the reasons behind the actions.
4. Possibility of Bias
It is not free from interviewer and respondent’s biasing effect. e.g., if the respondent knows that he is being observed, he is likely to act differently.
5. Not suitable for Short Events
It is not possible and advisable to observe events of short term duration. e.g., instead of observing a person listening to a programme, it is better to ask questions directly.