Among the more recently described is one known as the Evaluability Bias. It is "the tendency to weight the importance of an attribute in proportion to its ease of evaluation, rather than based on criteria that are deemed as more relevant after reflection." [Caviola, et al. 2014] Said differently, when assessing the value of an option, we assign importance to the option's attributes. The Evaluability Bias causes us to tend to assign too little importance to attributes that are relatively difficult to evaluate, and too much importance to attributes that are relatively easy to evaluate.

What Evaluability Bias is

Caviola et al. provide a careful study of this phenomenon in the domain of charitable giving. They find that when deciding which charities to support, donors tend to assign too much importance to the "overhead ratio," an easily measured attribute that corresponds to the ratio of administrative expenses to total donations. And donors assign too little importance to cost-effectiveness, which is a much more difficult-to-measure quantity that is, essentially, the value of good works done per unit value of donations.

We can Evaluability Bias causes us to tend to assign too
little importance to attributes that are relatively
difficult to evaluate, and too much importance
to attributes that are relatively easy to evaluateunderstand other cognitive biases, described earlier in the history of cognitive biases, in terms of Evaluability Bias. One example is a bias known as scope insensitivity or scope neglect. [Kahneman 2000] Originally named extension neglect by Kahneman, scope neglect is the tendency to assign inappropriately low weight to the quantity, scale, or scope of the option in question. For example, when comparing the importance of abuse of different drugs, people tend not to take into account the scale of the drug's abuse: differences in the number of abusers of each drug.

Evaluability Bias and technical debt

In the workplace, Evaluability Bias can have alarmingly deleterious effects. For example, nearly every organization depends on rational decision-making in the context of software development, either because they produce software products, or because they have business technology functions that produce software for internal use.

And because technical debt is a live issue that can afflict all software, it's important to make rational decisions about retiring existing technical debt and about preventing formation of new technical debt. Evaluability Bias is relevant because those decisions inevitably involve choosing which instances of technical debt we will retire. One of the important attributes of these choices is the cost of not retiring it. The cost of not retiring a specific class or instance of technical debt is often neglected, but even when we consider it, it is an attribute most notoriously difficult to measure.

Last words

When consider training for ourselves or for others, we tend not to consider training in limiting the effects of cognitive biases in decision-making. Surely it would be helpful, even if calculating its value with any useful degree of accuracy would be challenging. Evaluability Bias, ironically, might be playing a role in preventing organizations from training their people in methods for limiting the effects of Evaluability Bias.