When a researcher makes incorrect conclusions about their research, the validity type that is most threatened is:
D. Statistical conclusion validity
Statistical conclusion validity refers to the accuracy of conclusions drawn from statistical analyses, including whether the observed relationships or effects in the data are genuine or due to chance. If incorrect conclusions are made, it suggests that there may have been issues with the statistical methods or analyses used, which directly impacts this type of validity.
While other types of validity (construct, internal, external) can also be influenced by various factors in the research design and execution, the core issue of making incorrect conclusions primarily relates to statistical conclusion validity.