Internal Validity: Internal validity is the extent to which a study can establish a causal relationship between an independent variable and a dependent variable, free from the influence of confounding factors.
Ecological Validity: Ecological validity refers to the extent to which research findings can be applied to real-world, natural settings and situations, reflecting the actual experiences of participants.
Sampling Bias: Sampling bias occurs when the sample used in a study is not representative of the target population, limiting the ability to generalize the findings.