Those who research,internal/external validity

[psych844]

---

Members do not see this ad.

So sorry if this is not the right forum (not sure if there is a help forum for studying about psychology) but I'm taking an intro research methods course.

Does more externally validity mean the same thing as high level of externally validity? And why does more externally validity mean that there are MORE variables that can influence leading to less internal validity? wouldn't it be less variables not more?

 

[WisNeuro]

So sorry if this is not the right forum (not sure if there is a help forum for studying about psychology) but I'm taking an intro research methods course.

Does more externally validity mean the same thing as high level of externally validity? And why does more externally validity mean that there are MORE variables that can influence leading to less internal validity? wouldn't it be less variables not more?

This is more of a professional issues board. I'm sure someone would be willing to help you out though. But beforehand, at least provide us with your reasoning as you think through this question. What does it mean for something to have more or less internal/external validity?

 

[psych844]

This is more of a professional issues board. I'm sure someone would be willing to help you out though. But beforehand, at least provide us with your reasoning as you think through this question. What does it mean for something to have more or less internal/external validity?

Ok, well if something has internal validity it means that we can make a casual inference between independent/dependent variable. Ie if we are testing how a dosage of a certain drug impacts health..we can say that there is high internal validity because there are no threats (other variables) to threaten internal validity. This would include selection bias, history, maturation, right?

External refers to the fact if the results can be generalized to other people and situations. Part of being able to generalize is to make sure the experiment is realistic..so if one group of teens is made to watch a non-violent movie and another a violent one..then maybe have teens play some sport together (which would be realistic and a common thing for kids to do) you could question any part of that activity as contributing to the aggresion not neccesarily the movie?

 

[sockit]

Ok, well if something has internal validity it means that we can make a casual inference between independent/dependent variable. Ie if we are testing how a dosage of a certain drug impacts health..we can say that there is high internal validity because there are no threats (other variables) to threaten internal validity. This would include selection bias, history, maturation, right?

External refers to the fact if the results can be generalized to other people and situations. Part of being able to generalize is to make sure the experiment is realistic..so if one group of teens is made to watch a non-violent movie and another a violent one..then maybe have teens play some sport together (which would be realistic and a common thing for kids to do) you could question any part of that activity as contributing to the aggresion not neccesarily the movie?

I think it's a given that the tighter the experiment, the less able you are to generalize its conclusions.

 

[psych844]

Yeah that is the part I don't get.

In my example, the fact that the kids were asked to play hockey after both groups watched the telivision program would mean that it has high external validity..because the kids did a realistic activitity after doing the experiment we can generalize it, correct? But why does that decrease the internal validity?

I think it's a given that the tighter the experiment, the less able you are to generalize its conclusions.

 

[psych844]

Yeah. I get it now. I guess I'm tired cause yeah that is crazy simple to understand. lol