Final answer:
For his report, Roberto should use surveys and questionnaires as primary sources to gather direct and quantitative consumer feedback on the new backpacks.
Step-by-step explanation:
Roberto is writing a report to analyze a company's new backpacks' poor performance in the consumer market and needs to gather information for his analysis. The most appropriate primary sources he can use include surveys that ask customers for feedback and questionnaires that determine customer experience of the backpacks. These methods will provide direct insights from consumers and offer quantitative data which is essential in understanding customer satisfaction and preferences. Company reports on customer experience of previous backpacks, while useful, are considered secondary sources if they summarize the findings of prior research.