External Validity
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External Validity is defined as, “ the degree to which the results of research accurately generalize to other individuals and situations (Heiman, 2001, 64)”. The results of the study should give a good example of a relationship seen outside of that particular study (Heiman, 2001). External validity has specific subgroups that specific ally address one aspect of external validity. The most commonly mentioned sub-group of external validity is ecological validity (Heiman, 2001). Ecological validity is the extent to which research generalizes to a common behavior and natural situation (Heiman, 2001). If the research study does not include or maintain ecological validity, the study will only focus on the what participants did in the study and not on what they do in real life. Ecological validity is often lost as researchers try to increase internal validity, in which the researchers assign a task which controls too much for a behavior (Heiman, 2001). Researchers should aim to minimize any threats to external validity so that the study can be useful and practical for application or knowledge (Heiman, 2001). One way researchers could reduce threats to external validity is by controlling for extraneous variables which influence the data (Heiman, 2001). There are three ways one can control for these extraneous variables (Heiman, 2001). The most useful way to control for an extraneous variable is to identify and then eliminate the variable (Heiman, 2001). Sometimes it is not possible to eliminate an extraneous variable, therefore, the researchers keep the variable constant (Heiman, 2001). An example which illustrates the act of keeping an extraneous variable constant act of keeping room temperature constant (Heiman, 2001). The last common practice for eliminating extraneous variables is balancing them (Heiman, 2001).
The Second Life virtual study significantly focused on external validity, or the generalization of behaviors in the study to behaviors found in a natural setting. The study stated that there are two rules in the real world which are maintained in the virtual world despite little realism due to unnatural phenomena which occur. These rules include keeping an interpersonal distance between oneself and others and refraining from staring. The combination of these two events is a balance in which interpersonal distance will determine how much eye contact or staring is acceptable for the comfort of an individual. This is commonly known as the elevator effect. The participants in second life often keep a distance between the characters. The researchers broke this social rule by nearing their character to other characters which were controlled by participants. The participants reacted by moving their characters away from the characters who invaded their interpersonal space. This reaction occurs both in real life and in the virtual world. Researchers also broke the rule of eye contact and staring by having their character stare at other people’s characters. Once again, the characters reacted as they would in the real world, by moving away from the character in order to maintain a safe boundry. Future research using second life should attempt to find any other generalized behaviors from the real world.
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