Types of Biases

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Potential biases: see below

Other side: The other side of this debate constructed their argument very logically, health benefits, family benefits and other social benefits. However, as was pointed out by the opposing team, several of their statistics are biased. For example “College graduates live 6 years longer than those without a college degree”. This statistic has healthy user bias, since those attending college may have come from more privileged families that have better nutrition and healthier lifestyles than those that didn’t go to college. In fact, many of the statistics used could be biased in the same way, for example “mothers with only a high school education are 31% more likely to give birth to a low-birth weight baby than a woman with a college degree.

Benefits of Red Wine:

Who won: Anti red wine has health benefits

Most compelling evidence: This team effectively used credible sources of information and provided a structured argument using statistics. They also were able to point out a significant bias in the opposing teams arguments. One was that the beneficial compounds cited by the opposition is present at varying degrees in different grape varieties and different wines. Therefore, it is very difficult to draw any conclusions about their health benefits via consumption of wine studies in humans. Another point made by this team was that those people that drink red wine are likely living healthier lifestyles independent of their wine consumption and therefore likely represents a healthy user bias.

Potential biases: This is one of the most difficult debate topics to argue because these studies are not typically done in a controlled way. Therefore many biases can be confounding the results. For example, recall bias. Study participants may not recall accurately their wine consumption. Another potential bias, as mentioned above, could be healthy user bias; those people that drink a glass of wine may actually live healthier life styles and represent a healthy user bias.

Other side: Although this side presented several statistics on the perceived health benefits of red wine and some of the compounds, the lack of control in these sorts of studies using humans casts a lot of doubt on the validity of the statistics and we were not compelled by their arguments. Especially because we believe that there are several types of biases that could be present, as discussed above.

Teacher Tenure:

Who won: Anti teacher tenure

Most compelling evidence: The anti teacher tenure arguments were the most compelling using statistics and logic very effectively to provide a persuasive argument. The most compelling evidence presented was around the point that tenure protects teachers that perform poorly. Specifically, they pointed out that 89% of school administrators will not fire a poorly performing tenured teacher. Although one could argue that that is because they are working on improving performance, they also stated that in Chicago, only 28.5% of students met expectations on standardized test while only 0.1% of teachers were dismissed for poor performance. These striking statistics were very compelling that teacher tenure leads to keeping bad teachers in the school systems. From a logical perspective, this team’s most compelling argument was that most teachers reach tenure not because they are being rewarded for a good job, but because they didn’t get fired during the probationary period.

Potential biases: A potential bias in the presented statistics could be selection bias. Since we don’t know how the data was collected for some of the cities cited in the arguments, it could be that the numbers represent some of the worst performing districts and not all districts.

Other side: This team presented a very compelling emotional argument, but didn’t use many statistics to support their position. In fact, it seemed that they were even suggesting that tenure WOULD be good if it were used PROPERLY “Tenure seems to be an easy target to attack for underperforming teachers but consider that tenure could be strengthened to support and empower the best teachers rather than insulate the very small minority of teachers who are actively disengaged. Tenure could be the lever that allows the most effective teachers to influence, coach and evaluate the performance of their peers.”