Mr. Cruz has been working on a research related to job satisfaction of different employees from different departments. Since the company has hundreds of employees in total the number of employees per department is also numerous. In his sample size, he needs to compute for the number of repondents who will be invited to answer the questionnaire. Unfortunately, instead of writing a letter to the department head to seek for the total number he directly went to each department and started head counting. What characteristic of research is not present?