Is there any possibility that one’s ability to conclude whether the intervention affects the outcome but not some other factors is affected?

Yes. It depends on your research design and specific research questions. In quasi-experimental design, for example, other factors that may affect the outcomes can be controlled through random assignment.

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It will arise when researchers interpret the sample data to other persons, other settings, and past or future situations falsely.

How about external validity threats?

Internal validity threats are experimental procedures, treatments or experiences of the participants that threaten the researcher’s ability to correctly interpret the data about the population in an experiment.

What do they represent?

Internal threats and external threats

What are they?

There are two types of threats to validity.

How many types of threats can we have?

Yes researchers should identify potential threats to the internal validity of the experiments and design them for minimizing or eliminating threats.