A multistage cluster sampling is a complex sampling technique, but is used quite frequently when the study does not come with a list of all of the members of a population and such a list is unable to be obtained. Due to not having this list, researchers need to balance the number of clusters and the size of each cluster in an attempt to achieve a certain sample size. Stratification can be used during this time to reduce sampling errors that may arise due to the lack of knowing the members of a population.
Probability proportionate to size is an efficient technique that researchers can use for multistage cluster sampling, which further helps to ensure accuracy and unbiased sampling. As with any part of research and observation, even if it is just in the writing process of the research article, ethics must be observed and ensured to those in the experiment and those that are reading about it. In regard to those that are reading the research articles, the researcher must make it known that there is always the probability for errors that might make the results misleading.
Science is not always an exact art, since other researchers and scientists are able to work off of previous studies to simply further the researcher. As such, a lot of this further research stems from inaccuracies or gaps in information in previous studies. Furthermore, when non-probability sampling methods are being used to obtain the breadth of variations in a population, the researcher needs to make it clear that the readers are not misled in regard to the variations and what is typical in the population.
Sampling is perhaps one of the more important aspects of a research study. The sample acts as the population as much as possible, either comparing behaviors or beliefs, or seeing how often something is undergone, all depending on the purpose of the study. Without the sample population, researchers cannot even begin to fathom the results of their research questions. Therefore, it becomes important that researchers understand the various types of sampling techniques that are available to them, and they need to be aware that they will always face errors in their research and that there are methods that can be undergone to decrease how many.
Chapter Eight Summary Experimentation is the heart and soul of any research or observation project. By conducting an experiment, researchers are able to focus on the important aspects of their research question, wether the variables are dependent or independent. In experiments, the researcher gathers a selected group of subjects, one that is based on the purpose or intended result of the experiment, does stuff to them (the experimental part) that can either provoke a wanted response or observe natural behaviors without outside influence, and then observe the effect of what took place.
Many topics can use experiments to understand old concepts, discover new information, or test information that is already available. Experiments provide a wonderful chance to implement controlled testing of casual processes. Though there are different methods of experiments and more are being designed as science and research evolves, the classic experiment is the one that is used most, being the tried-and-true method. The classical experiment involves the testing of an independent variable, or the experimental stimulus, on a dependent variable through various levels of testing of experimental and control groups.
The experimental and control groups must be similar to each other, something that is of great importance to the experiment. However, it is not as important for the experimental subjects to be representative of the larger population. Double-blind experiments, a special technique, disables experimenter bias, which causes the experimenter and the subject to be unaware of which subjects are in the control and experimental groups. Campbell and Stanley are the most vocal about experiments and their various forms.
They describe three different forms of pre-experiments, and they are as follows: the one-shot case study, the one-group pretest-posttest design, and the static-group comparison.
Read More