Hi there. I would like to talk about voluntary samples from statistics.
Sampling Objectives
A researcher wants to gather information on adult males and their exercise habits. It is time consuming and expensive to retrieve information from all adult males from a major city. Instead of getting all these adult males as a population, it is easier and cheaper to gather a sample from this population. Sampling refers to getting a portion of a designated population where you gather information from.
Sample Size
Sample size refers to how many people to gather for information from a population. Getting 5 people from a million people in a population is a small sample size. The information from 5 people is not sufficient enough to make conclusions from a 1 million population. Gathering 500,000 people from a population of 1 million is good in terms of information gain but it is costly and time intensive. The concept of sample size is technical and is for a potential different post.
There are different sampling methods out there when it comes to gathering information from people and items. Each sampling method has their own pros and cons when it comes to time factors, cost factors, information gain, random vs non-random and biases. In this post, I cover voluntary samples.
Volunteer Sampling
Volunteer sampling is a non-random sampling method where people voluntarily provide information to researchers. This type of sampling is common in psychology studies and clinical trials. You may have seen ads where the researchers are looking for participants that meet certain requirements for a study. A lot of these studies are in the form of clinical trials where volunteers agree to participate in a trial. Participants are often compensated with money or gift cards for their time and work if they completed the whole trial. There are cases where not everyone completes the trial so there will be missing information to deal with for the data analysts and researchers.
One popular form of volunteer sampling is product and service reviews. Reviews like Google Reviews, Amazon Reviews and Trustpilot can be seen as volunteer sampling. Many people don't see this as volunteer sampling but it is. Not everyone who uses a product or service gives a review so the reviews you see are from people who were willing to give a review. Reviews may or may not have text with their numerical review. In addition, reviews may or may not be based on actual experiences. When it comes to reviews, I do think you have to be careful with the ratings and some of the stuff people put out there. Some may be truthful or misleading.
Thank you for reading.