Internal Validity vs. External Validity 

thank you for this , been struggling to udnerstand this but youve made it clear.

good explanation, thanks for this

Thanks so much for this video.

Thank you!!!!

You are the best

Hi, could I ask if forced choice questions (whether A is better or B is better) would affect internal validity (since the participant might not be able to choose other options which he feels more inclined to)

Can you give me the link of this presentatiin , please