किसी शोध (अनुसंधान) की गहराई और विस्तार का अनुमान सर्वोत्तम रूप से किसके द्वारा लगाया जा सकता है?

A researcher wants to explore the effect of possible factors on the organization of effective computer-based learning interventions in schools. Which research method is most appropriate for this study?

Which of the following steps is NOT essential while designing a questionnaire?