List the three major methods of collecting data and explain their differences.

While launching a product, a company often requires several types of data regarding the feedback on the similar types of products produced by its competitors. For example, a new mobile producing company will try to get the data of the feedback received by its competitors and will accordingly work on its product before launching.

Thepublished sources from where the researchers collect data are books, journals, and even newspapers. The researchers in their research study mention the sources in a definite way from where the data is collected.

Designing experiments is often followed by different companies whenever they launch their products. The companies often distribute samples to their target audiences and accordingly form data sets based on their feedback.

Theobservational studies sometimes can take a long time because data collection is done based on the responses or actions taken by the sample units in different situations. Sometimes a researcher might take a few years to collect the data depending upon the objectives.