The Logic Behind Our Recommendation Algorithm

Ellie Baer
Apr 6, 2017 · 5 min read


The purpose of this thesis is to illuminate the decisions that we, Bridge the Media, have made regarding the reliability and bias of the news publications that we analyze.


Bridge the Media is a nonpartisan tool that exposes online news readers to opposing viewpoints. From the comfort of the viewer’s current reading routine, Bridge the Media will recommend an article on a similar topic from a contrary angle. The algorithm matches inverse levels of bias with equivalent levels of reliability in order to uphold the reputation and trust of our tool. In our research, we have aimed to approach each publication with as little bias as possible, taking into account human error. Because bias and reliability can be interpreted in various manners, we have fleshed out the details of our approach and analysis and included information we used to come to our conclusions in this thesis. We’re committed to transparency and think it’s important for Bridge the Media users to understand why we drew the conclusions that we did.


Bias has historically been incredibly difficult to accurately identify, due to the inherent bias of the individual conducting research. We understand that there is not necessarily a “correct” answer and that, oftentimes, there will be a high level of controversy associated with whatever judgments are made on our part. Bridge the Media uses a scale to rank bias for each news publication chosen. The scale uses a numerical digit to quantify a generalized description. Highly partisan liberal (+3), partisan liberal (+2), leaning liberal (+1), minimal bias (0), leaning conservative (-1), partisan conservative (-2), and highly partisan conservative (-3).

One level deeper, we also have defined the terms “conservative” and “liberal” to be used for our analysis.

The first issue that needs to be addressed is the confusion between Democratic and liberal, and conversely, Republican and conservative. It’s important to understand the landscape in which these terms exist and how they interact with each other. Given high levels of political party polarization, voters have turned in recent years to their party affiliation; ideologies are more clearly reflected in political parties than ever before. We see far fewer liberal Republicans and conservative Democrats than we did in the 1980s. According to James E. Campbell, a political science professor with University of Buffalo SUNY and distinguished author, approximately half of the American population in 1972 identified themselves as either liberal or conservative, with the other half self identifying as moderate. However, in 2015 the split was 56% liberal or conservative, with only 44% identifying as moderate. (We have rated Campbell’s bias as +1). As a matter of fact, during the 20th century as late as the 1970s, the Democratic party was the party of conservative values, segregation, and limited government regulation. Thus, Bridge the Media has ranked bias in terms of liberal and conservative, instead of Democratic and Republican.

There are two main schools of thought per the philosophy of liberalism; classical liberalism and modern liberalism.

Classical liberalism was formed from the philosophy of liberty found in the Declaration of Independence. Most people at the time believed that the government gave them their rights, and had the power to take them away. Jefferson argued at the time that rights are in fact part of human nature, and that the government is there solely to protect these rights. This classical liberalism experienced great popularity throughout the 19th century.

Modern liberalism has amplified these views. It is defined as a political philosophy based on “belief in progress, the essential goodness of the human race, and the autonomy of the individual and standing for the protection of political and civil liberties…a philosophy that considers government as a crucial instrument for amelioration of social inequalities (such as those involving race, gender, or class).” Modern liberalism econmpasses an emphasized need for government intervention, high importance placed on social issues, public education, and social equality. Liberal thought places a lower importance on national defense, free markets, individual liberty, and fiscal responsibility. A major liberal focus is social inequality and its implications on wealth distribution and equal access and opportunity.

Conservatism can be defined in more stagnant terms. Conservatism is defined as a “political philosophy based on tradition and social stability, stressing established institutions and preferring gradual development to abrupt change…such a philosophy calling for lower taxes, limited government regulation of business and investing, a strong national defense, and individual financial responsibility for personal needs (as retirement income or health-care coverage).” Conservatives typically place a lower importance on social issues, public education, and widespread equality. Many conservative beliefs are surrounded by Judeo-Christian sensibilities, including stances on abortion and LGBT issues.

Conservative Americans are “far more willing than liberalism to restrict freedom of thought and expression” and place additional government regulations on noneconomic liberties, argues John Goodman, founder of the National Center for Policy Analysis and has been praised by the Wall Street Journal over recent years for his work in healthcare. We have rated his bias as (-1). Business, he argues, is none of the government’s business according to conservatives.


The reliability scale was slightly easier to make, given that the definition of reliability is more static and less controversial than that of bias. Although the differences between some of the reliability measures may seem minute, we believe that they are crucial in identifying the nuances of news publications. We used the Merriam-Webster definition of reliability to guide our research, which defines reliability as “the extent to which an experiment, test, or measuring procedure yields the same results on repeated trials.”

The rank of reliable is defined as no doubt of authenticity, trustworthiness, or competency; history of complete reliability. Usually reliable is defined as minor doubt about authenticity, trustworthiness, or competency; and has a history of valid information most of the time. A fairly reliable source has doubt of authenticity, trustworthiness, or competency but has provided valid information in the past. A source ranked not usually reliable provides significant doubt about authenticity, trustworthiness, or competency but has provided valid information in the past, and an unreliable source lacks in authenticity, trustworthiness, or competency; with a history of invalid information. Our final measure is cannot be judged, where no basis exists for evaluating the reliability of the source.

Intersection of Bias and Reliability

The scale visually takes place on four planes that identify both bias and reliability. The way that Bridge the Media matches bias and reliability is in two different ways per each factor. Reliability is matched up with the reliability directly proportional on a plane. For example, a source that has been marked as usually reliable is matched with an article that, too, has been ranked as usually reliable.

Bias has been matched up by choosing an source with a bias level diametrically opposing its own bias, which is why bias has been ranked with both positive and negative numbers. A -2 source (partisan conservative) is matched with an article from a source we have labeled as +2 (partisan liberal).


Bias is an incredibly difficult and loaded topic. We understand that the views expressed through the Bridge the Media tool and on our blog will not necessarily adhere to the ideologies of all those who read it. That being said, the point of this tool is to shed light on the polarized media that is fed to us every day. We’re open to disagreements and feedback and encourage all of our users to reach out to us with any concerns or issues.

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