In scientific research, sampling is defined as the thorough and systematic selection of study subjects, which must be carried out in a way that is verifiable to outside observers and as free as possible from error or bias. For this project, you will make use of Craigslist (Links to an external site.), a website that posts job ads, housing rentals, or other sale items. To draw a random sample of 25 advertisements, you should select a city that is at least equal to the size of Minneapolis-St. Paul.
- Choose a classified ad page on Craigslist under one of the following categories: Housing, For Sale, or Jobs. Copy the URL on which the ad listings appear and save it to include in your discussion post.
- Select the “list” view option and copy/paste the listings into a document file. Number each ad consecutively and note the total number of ads.
- Using a random sampling strategy of your choosing (e.g., Simple Random Sampling; Systematic Random Sampling; Stratified Random Sampling), select the ads to be included in your ad and highlight them in your document.
- Choose one or two characteristics that you will identify in each ad. These might be the type of job or housing or item advertised, the community where the advertisement is located, whether the asking price/rent/salary is listed, or the asking price/rent/salary itself. As you scan the highlighted ads, record these characteristics for analysis.
- Tally up the characteristics (for example, how many housing ads listed an asking price and how many didn’t?) Calculate an arithmetic average for the prices/rents/salaries you recorded (add up all the prices or salaries and then divide by the total number of prices or salaries listed.) These are your sample statistics.
- Post a summary of your sample statistics, a description of your sampling method, and the URL of your ad listings to the discussion forum. Write a brief statement discussing whether you think your sample accurately reflects the population of ads in your listings.
- Compare your sample statistics with those of at least two your classmates and discuss whether you think your samples accurately reflect the populations of your ad listings.