# Availability Bias: Categorization

I am confused between the explanation in the CFA book and schweser. Shcweser describes categorization as the bias of emphasizing on how an idea is first categorized (which seems to me similiar to representativeness bias).

However in the curriculum, talks about this bias differently. Categorization bias is the bias resulting from difficulty arising from coming up with a search set.

“When solving problems, people gather information from what they perceive as relevant search sets. Different problems require different search sets, which are often based on familiar categorizations. If it is difficult to come up with a search set, the estimated probability of an event may be biased. For example, if an American is asked to come up with a list of famous baseball players and a list of famous soccer players, the list of soccer players is likely to be quite short. This assignment might lead the American to erroneously conclude that there are fewer famous soccer players than baseball players.”

Can someone kindly explain to me what categorization bias really means and why does it seem different under the two books?

Just dropping by on a post-Thanksgiving morning and to see this… a new bias?

There was a mnemonic online somewhere about the biases/errors. Should look for that and I do not believe categorization is part of it.

focus on the more popular ones

RBclassify new information based on past experiences and classifications.The new information superficially resembles (represent) familiar elements already classified, but in reality it can be very different.

Base-rate neglect and sample-size neglect are two types of representativeness bias. In BRN FMPs tend to underweight the base rates and overweight the new information (which is opp of conservatism bias). In sample - size neglect, FMPs incorrectly assume that small sample sizes are representative of populations.

The availability bias is a rule of thumb that allows people to estimate the probability of an outcome based on how familiar that outcome appears in their lives. Categorisation is a type of availability bias. In categorization, people attempt to categorize or summon information that matches a certain reference. The first thing that their brains do is generate a set of search terms, specific to the task at hand, that will allow them to efficiently navigate their brain’s classification structure and locate the data they need. Different tasks require different search sets, however; and when it is difficult to put together a framework for a search, people often mistakenly conclude that the search simply references a more meager array of results. For example, if a French person simultaneously tries to come up with a list of high-quality U.S. vineyards and a corresponding list of French vineyards, the list of U.S. vineyards is likely to prove more difficult to create. The French person, as a result, might predict that high-quality U.S. vineyards exist with a lower probability than famous French vineyards, even if this is not necessarily the case.