In this particular case, you are the only one who has not fallen ill. The only difference between you and others is that you didn`t eat a salad. This is probably the cause of other people`s illnesses. This is an application of the method of difference. This rule states that if you have a situation that has one effect, and another that does not, and the only difference is the presence of a single factor in the first situation, we can deduce this factor as the cause of the effect. Symbolically, the accompanying variation method can be presented as (with ± that represent a displacement): “Compliance method”. Merriam-Webster.com dictionary, merriam weaver, www.merriam-webster.com/dictionary/method%20of%20agreement. Retrieved November 30, 2020. Determining exact cause and effect is not an easy task.
We can often confuse them or misinterpret them because we lack sufficient information. Mill`s methods are attempts to isolate a cause from a complex sequence of events. Symbolically, the common method of consistency and difference can be presented as follows: it is important that there are no uniform criteria for what constitute acceptable limits of conformity. This is a subjective decision that must be made from a clinical point of view and must depend on and pre-specify the variable to be measured. Why is this important? Well, after clinicaltrials.gov, the number of trials using Bland-Altman as primary analysis appears, but further study of some of these studies shows that this methodology is often misused and that sample size calculations are not properly taken into account. Chhapola et al (2015) found that there is an incomplete report on the Bland Altman methodology in published clinical trials and find: “Despite their simplicity, B-A does not seem to be fully understood by researchers, reviewers and magazine publishers.”  With the growing need to compare measurement methods, the use of the Bland Altman methodology will also increase and, as statisticians, we play a key role in ensuring that it is properly applied. Mill`s methods should come as no surprise, as these rules articulate some of the principles we implicitly use in cause-and-effect reasoning in everyday life. However, it is important to respect the limits of these rules.
For a property to be a necessary condition, it must always be present when the effect is present. As is the case, it is in our interest to examine cases where the effect is present and to take into account the properties present and those that are considered “possible necessary conditions”. .