What are the different threats to external validity in experimental research?

There are several threats to external validity in experimental research. These include:

1. Selection bias: This occurs when the participants in the study are not representative of the larger population, leading to limited generalizability of the findings.

2. Reactive or interaction effects: The presence of the researcher or the experimental setting may influence participants' behavior, leading to results that may not be applicable in real-world situations.

3. Experimental mortality: This refers to the loss of participants during the course of the study, which can affect the representativeness of the sample and the generalizability of the results.

4. Experimenter bias: This occurs when the researcher's expectations or biases influence the participants' behavior or the interpretation of the results, potentially compromising the external validity.

5. Demand characteristics: Participants may alter their behavior or responses based on their perception of the study's purpose or the expected outcomes, leading to results that may not accurately reflect real-world behavior.

6. Time-related threats: The passage of time between the study and the application of the findings can affect the external validity, as societal or contextual changes may render the results less applicable.

7. Sampling bias: This refers to the non-random selection of participants, which can limit the generalizability of the findings to the larger population.

8. Contextual factors: The specific conditions or settings in which the experiment is conducted may not accurately represent real-world situations, limiting the external validity of the results.

It is important for researchers to be aware of these threats and take appropriate measures to minimize their impact in order to enhance the external validity of their experimental research.