The method of agreement is a powerful tool in determining cause and effect relationships in research. It is based on the principle that if two or more instances of a phenomenon share a common factor, that factor is likely to be the cause of the phenomenon. Therefore, the conclusion of the method of agreement should be certain, as it relies on empirical evidence.

However, there are some limitations to the method of agreement that can affect the certainty of the conclusion. Firstly, the method relies on the researcher`s ability to identify and control all relevant variables. If the researcher overlooks a crucial variable, the conclusion may not be accurate.

Secondly, the method of agreement assumes that the relationship between the cause and effect is constant across all instances. This may not always be the case, as there may be other factors that influence the phenomenon in different contexts.

Moreover, the method of agreement does not provide an explanation for why the cause is responsible for the effect. It only identifies the relationship between the two. Therefore, further research may be needed to understand the underlying mechanism.

To mitigate these limitations, researchers often use other methods, such as the method of difference or the method of concomitant variation, to triangulate their findings and increase the certainty of their conclusions.

In conclusion, while the method of agreement is a useful tool in identifying cause and effect relationships, the certainty of the conclusion may be affected by limitations such as the researcher`s ability to control all relevant variables, the assumption of constant relationships, and the lack of explanatory power. Therefore, it is important to use multiple methods and conduct further research to increase the certainty of any conclusions.