accurate judgment. This is because humans can easily control what they say to present themselves in a particular light or provide a certain impression of a situation but have a more difficult time trying to control their facial and body expression and tone of voice. For example, judges were found to reveal their true expectations of whether or not a defendant was guilty through their nonverbal behavior but not their verbal behavior. However, Ambady and Rosenthal's meta-analysis revealed that while judgments were more accurate when observing only facial and body expressions as opposed to facial and body expressions in addition to speech, the difference in accuracy is not significant enough to actually declare that using different channels of communication will affect the accuracy of a result. Physical attractiveness In Ambady and Rosenthal's 1993 experiment, they use 2, 5 and 10 second video clips of non-verbal behavior of teachers to test the accuracy of the judgments made by raters who watched those videos. While physical attractiveness of the video subject may seem like an obvious bias that may lead people to form inaccurate judgments, they demonstrated that it actually did not have a strong effect on their experimental outcome. One reason may be due to differences in the "type" of thin slice that is being made available to the raters. For example, when simply given a photo of an individual, a rater tends to judge personality traits simply based on attractiveness. However, when expressive behavior is available such as through the video clips used in the experiment, physical attractiveness becomes less important and less utilized when forming an impression of someone. Practical implications While thin-slicing has been proven to be a powerful experimental tool, it is important that experiments are being designed such that thin-slicing can actually be used to accurately judge the behavior of interest because it is not appropriate to use thin-slicing to universally evaluate different situations. First, the behaviors or traits in question should be easily observable so that ratings based on thin-slicing can be used reliably. Second, these traits should generally have an affective or interpersonally, rather than personally-oriented component because the latter is much more difficult to judge and less observable. Interpersonal dimensions include dominance and shyness while personal dimensions include conscientiousness and intelligence. The proven accuracy and effects of thin-slicing has several practical implications. First, experimenters can reliably use thin-slicing to evaluate different affect variables