Problem:
Can you help with come up with a reply to this discussion board?
Part 1:
Gravetter and Forzano (2018) explains that external validity means how well the results apply to other people outside the study. The three threats are participant reactivity, interaction of selection and treatment, and artificial setting. Participant reactivity is when people change how they act because they know they are being studied. For example, basketball player may try harder during a game just because a college coach is watching them. Interaction of selection and treatment is what happens when results only apply to a specific group, such as third graders only and not the whole population. Lastly, artificial setting is when a study is done in a lab such as rats being tested on for medicine and vaccines. According to Gravetter & Forzano (2018), there are 3 common threats to internal validity, which are history, maturation, and testing efforts. History is when something outside the study happens during the experiment and changes the results such as a star player gets injured before a game, now the game results may not be what the fans want. Next is maturation, which refers to natural changes in participants, such as fans getting tired or stressed while or after watching a game. Lastly, testing effects is when participants could change their answers the next time around because they have already taken the test. (Gravetter & Forzano, 2018).
For my capstone project on sports fans' emotions, a threat to external validity is that my participants might only be college students, so my results may not apply to all sports fans. A threat to internal validity is history, because a major sports event, like a championship game, could influence emotions during my data collection. To reduce these threats, I can include participants from different ages and backgrounds and collect data across multiple games. Need Assignment Help?
Part 2
A between-subjects design uses different participants for each condition. For example, when it comes to sports; one group watches a team win, and another group watches the team lose.
A within-subjects design uses the same participants in every condition. The same fans experience winning and losing and report their emotions each time.
According to Gravetter & Forzano (2018), one difference is that between-subjects designs can have group differences, like one group being more emotional than the other. Within-subjects designs reduce this problem because the same people are compared to themselves. But it must be noted that within-subjects designs can have order effects, such as participants getting tired or learning from earlier tests. You cannot make a study have perfect internal validity and perfect external validity at the same time. If you control everything tightly to improve internal validity, the study may not feel real and may not apply to real life. If you make the study more natural to improve external validity, you lose control over variables, which can affect the results (Gravetter & Forzano, 2018). I believe that this is why psychology cannot prove things with 100% certainty. Instead, it gives strong evidence based on careful research.