Identify the advantages and disadvantages of the following job analysis techniques Observation method, Structured Questionnaire method and Diary method

Observation method: Advantages: 1.Firsthand information; 2.Simple to use; 3.Verifies data from other sources; 4.Useful for manual and psycho motor tasks.// Disadvantages: 1.Time consuming; 2.May bias worker performance; 3.Small sample size; 4.Requires skilled observer; 5.Validity & reliability may be problematic.// 

Structured Questionnaire method: Advantages: 1.Does not require trained interviewer. 2.Relatively less expensive. 3.Can reach more workers. 4.Data is standardized (structured).// Disadvantages: 1.May be difficult to construct. 2.May have low response rate. 3.Responses may be incomplete. 4.Responses may be difficult to interpret (open-ended).// 

Diary method: Advantages: 1. Collects data as events happen. Disadvantages:1.Consistent and continuous entries may be difficult to obtain. 2.Data not in standardized format.