In contrast to agricultural systems, natural systems often have more than one species as a source of inoculum that will contribute to disease levels (Barnes et al. 2005). A common pathogen found in the tallgrass prairie is Puccinia andropogonis, the causal agent of leaf rust on big bluestem (Andropogon gerardii).
https://www.apsnet.org/edcenter/advanced/topics/EcologyAndEpidemiologyInR/SpatialAnalysis/Pages/CaseStudy1PearsonCorrelationAnalysis.aspx
1 Case studies allow for the development of novel hypotheses for later testing, provide detailed descriptions of rare events, and can explore the intricacies of existing theories of causation.  Case studies cannot directly indicate cause and effect relationships or test hypotheses.
https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/researching-psychology-2/methods-of-collecting-data-28/case-studies-128-12663/
Try to have 30 or more participants; this is important to increase the validity of the research. Your hypothesis might be that there is a positive correlation (for example, the number of hours of study & your midterm exam scores), or a negative correlation (for example, your levels of stress & your exam scores). A perfect correlation would be an r = +1.0 & -1.0, while no correlation would be r = 0.
https://capilanou.ca/psychology/student-resources/research-guidelines/Correlational-Research-Guidelines/
While correlational research can suggest that there is a relationship between two variables, it cannot prove that one variable causes a change in another variable. In other words, correlation does not equal causation.
https://www.verywell.com/correlational-research-2795774
APS > Education > Advanced > Topics in Plant Pathology > Ecology and Epidemiology in R > Spatial Analysis > Case Study #1: Pearson Correlation Analysis. The spatial pattern of disease is often analyzed to draw inference about transmission or spread of the disease (Barnes et al. 2005). The spatial patterns of heteroecious rust fungi can be especially interesting. Studies of the spatial scale at which hosts and pathogens interact in natural systems may lead to better understanding of the evolution of resistance or virulence in plant and pathogen populations (Thrall and Burdon 1997).
https://www.apsnet.org/edcenter/advanced/topics/EcologyAndEpidemiologyInR/SpatialAnalysis/Pages/CaseStudy1PearsonCorrelationAnalysis.aspx
Another important thing to note is that while correlational research can reveal if a relationship exists between variables, this kind of research cannot prove that changes to one variable lead to changes to another variable. In other words, correlational studies cannot prove cause-and-effect relationships.
https://www.verywell.com/correlational-research-2795774
In general, a correlational study is a quantitative method of research in which you have 2 or more quantitative variables from the same group of subjects, & you are trying to determine if there is a relationship (or covariation) between the 2 variables (a similarity between them, not a difference between their means).
https://capilanou.ca/psychology/student-resources/research-guidelines/Correlational-Research-Guidelines/
The Purpose of Correlational Research. Correlational studies are used to look for relationships between variables. There are three possible results of a correlational study: a positive correlation, a negative correlation, and no correlation. The correlation coefficient is a measure of correlation strength and can range from –1.00 to +1.00.
https://www.verywell.com/correlational-research-2795774
Correlational studies are a type of research often used in psychology as a preliminary way to gather information about a topic or in situations where performing an experiment is not possible. The correlational method involves looking at relationships between two or more variables.
https://www.verywell.com/correlational-research-2795774
With the use of the Excel program, calculating correlations is probably the easiest data to analyze. In Excel, set up three columns: Subject #, Variable 1 (e.g. hours of study), & Variable 2 (e.g. exam scores). Then enter your data in these columns. Select a cell for the correlation to appear in & label it.
https://capilanou.ca/psychology/student-resources/research-guidelines/Correlational-Research-Guidelines/
what is a correlational case study?
A correlational case study is a type of research often used in psychology as a preliminary way to gather information about a topic or in situations where performing an experiment is not possible.