Language
Country/Area
No result found
Why do some researchers fail to control their experimental variables? Uncovering the secrets of observational studies!
In many fields of research, such as epidemiology, social sciences, psychology, and statistics, observational research is a method of making inferences about a population from a sample. However, in such studies, the independent variables are often not under the control of the researchers, mainly because of ethical considerations or other logistical constraints. This article will explore the characteristics of observational studies and why, in some cases, researchers cannot control their experimental variables.
The characteristic of observational studies is the lack of a random allocation mechanism, which naturally brings difficulties to inferential analysis.
Difficulty in controlling independent variables
The difficulty in controlling independent variables arises from a variety of reasons. First, conducting randomized experiments would violate ethical standards in many cases. For example, if a researcher wishes to investigate a hypothesized link between abortion and breast cancer, in a theoretical controlled experiment the researcher might randomly assign pregnant women to an “experimental” group who receive an abortion and a “control group” who do not. control group", but this would violate many social ethical principles. Moreover, it is difficult for such experiments to overcome various confounding problems.
Many published studies have been conducted on a group of women who had undergone abortions, a group over which the researchers had no control.
Another example is that if a scientist wants to study the public health effects of a community ban on smoking in public indoor areas, a controlled experiment would require randomly selecting some communities to be included in the experimental group, but usually the driving force behind such legal actions is the community and its legislature. responsibility, and the researcher often lacks the political power to push for a law.
Types of Observational Studies
There are several different types of observational studies:
- Case-control study: A study designed to compare two groups with different outcomes and to make a contrast based on some assumed causal property.
- Cross-sectional study: Data are collected from the entire population or a representative subset at a specific point in time.
- Longitudinal study: A correlation study that involves observing the same variables multiple times over a long period of time.
The usefulness and reliability of observational studies
Although observational studies cannot be used to make definitive statements about the safety, effectiveness, or efficacy of a practice, they can still provide a lot of useful information. These studies help identify signals in practice, form hypotheses, and provide foundational data for subsequent experiments. The use of these studies is particularly important in the medical and social sciences.
Observational studies can provide information on “real world” use and practice.
Deviation and compensation methods
A major challenge of observational studies is to avoid the influence of overt biases and assess the impact of potential hidden biases while drawing acceptable conclusions. Researchers can use various statistical techniques, such as matching techniques, to minimize the impact of these biases on their results.
Matching technology deviation
Researchers may employ multivariate statistical techniques to approach experimental control through matching methods. Although these methods are able to take into account the influence of observational factors, they have also been criticized because they may further exacerbate the so-called confounding problem.
Selection bias
Another difficulty with observational studies is that researchers may be biased in their observational skills. They may inadvertently look for data that are consistent with their research conclusions, which introduces selection bias, and certain variables may be systematically mismeasured at any stage of the study.
Overall qualityAccording to recent research, the results of observational studies are similar to those of randomized controlled trials, showing similar effects. This tells us that although observational studies have their limitations, they can also provide reliable data for future research design and clinical practice.
In summary, the difficulty in controlling independent variables poses a challenge to observational studies; however, with appropriate methods and techniques, these studies can still provide us with valuable resources. In modern scientific research, which is full of uncertainty, should we place more emphasis on the knowledge fostered by these observational studies?
