In: Math
Suppose a researcher is collecting data about the amount of soda Americans consume in one day. If the researcher was to gather two separate representative samples from the population, differences may exist between these samples. These differences may be attributed to what?
The difference between the 2 samples may be because of one or more of the following reasons:
1) The samples might be of different sizes - this can be because of the relative ease and outreach of the sampling method used in the 2 cases. Speaking to people individually might be less penetrating than sending out emails with attached offers to a large emailing list.
2) Socioeconomic status of the population targeted for the 2 samples - if the social and economic statuses of the 2 samples vary significantly, the samples could be considerably different in terms of the relative amounts of soda consumed.
3) Seasons when the samples were collected - if one sample was collected during summers while the other one during, say, winters, the former sample can be expected to have higher values since soda consumption is generally higher during hotter months owing to higher sales of soft drinks among others.
4) Areas where the samples were collected - hotter areas could give higher soda consumptions compared to cooler areas.