When teaching, we researchers used to use the language which is not smooth for the research's learners. You can attend the training and hear one saying that, “the secondary data is not reliable and when using it you should be careful". So, idle know which kind of carefulness is spoken. You can listen to another lecture you hear the speaker against primary data saying that, “during data collection, the researcher may find the respondent in the bad mood and get different information compared to another time when find the same respondent providing different information”. He/she goes on saying, “also the researcher may have poor knowledge on data collection in dynamics situations, so that may provoke the respondent and give biased data. So, it is better to use the database developed by professional organizations with resources well trained in data collection (secondary data). These people (trainers) confuse me much with their teachings. I knew that, choosing the type of research whether secondary or primary, may depend to the type of the study. For example, if you need to study on macroeconomic variables, organizations’ performance, etc, you have to use secondary data as accounting information are always historical in nature. So, how can one measure the performance without using financial statements which are historical and secondary in nature? Or, how can one measure the behavior of the environment without including primary data or qualitative? confused.