Commonplace

“Chesterton’s Fence” is the principle that reforms should not be made until the reasoning behind the existing state of affairs is understood.

The Lindy effect (also known as Lindy’s law) is a theorized phenomenon by which the future life expectancy of some non-perishable thing, like a technology or an idea, is proportional to its current age. Thus, the Lindy effect proposes the longer a period something has survived to exist or be used in the present, the longer its remaining life expectancy.

The more any quantitative social indicator is used for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor.

Goodhart’s law is an adage that has been stated as, “When a measure becomes a target, it ceases to be a good measure”. It is named after British economist Charles Goodhart, who is credited with expressing the core idea of the adage in a 1975 article on monetary policy in the United Kingdom:

Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes.

The Jevons paradox […] or Jevons effect is an economic phenomenon said to occur when technological improvements that increase the efficiency of a resource’s use lead to a rise, rather than a fall, in total consumption of that resource. Greater efficiency reduces the amount of the resource needed per application, lowering its effective cost; if demand is sufficiently price elastic, this induces demand, frequently resulting in a net increase of total resource consumption.

In economics, a perverse incentive is an incentive structure with undesirable results, particularly one where those effects are unexpected and contrary to the intentions of its designers.

The results of a perverse incentive scheme are also sometimes called cobra effect, where people are incentivized to make a problem worse.

Betteridge’s law of headlines is an adage that states: “Any headline that ends in a question mark can be answered by the word no.” It is based on the assumption that if the publishers were confident that the answer was yes, they would have presented it as an assertion; by presenting it as a question, they are not accountable for whether it is correct or not.

Cunningham’s Law states “the best way to get the right answer on the internet is not to ask a question; it’s to post the wrong answer.”

The concept is named after Ward Cunningham, the inventor of wiki software. According to the law’s author, Steven McGeady, Wikipedia may be the most well-known demonstration of this law.

In a speech in 2002, Crichton coined the term “Gell-Mann amnesia effect” to describe the phenomenon of experts reading articles within their fields of expertise and finding them to be error-ridden and full of misunderstanding, but seemingly forgetting those experiences when reading articles in the same publications written on topics outside of their fields of expertise, which they believe to be credible.

The law is based on the reasoning that in order for a product to function, the authors and designers of its component parts must communicate with each other in order to ensure compatibility between the components. Therefore, the technical structure of a system will reflect the social boundaries of the organizations that produced it, across which communication is more difficult.

Hofstadter’s law is a self-referential adage, coined by Douglas Hofstadter in his book Gödel, Escher, Bach: An Eternal Golden Braid (1979) to describe the widely experienced difficulty of accurately estimating the time it will take to complete tasks of substantial complexity:

Hofstadter’s law: It always takes longer than you expect, even when you take into account Hofstadter’s law.

The law of triviality is C. Northcote Parkinson’s 1957 argument that people within an organization commonly give disproportionate weight to trivial issues. Parkinson provides the example of a fictional committee whose job was to approve the plans for a nuclear power plant spending the majority of its time on discussions about relatively minor but easy-to-grasp issues, such as what materials to use for the staff bicycle shed, while neglecting the proposed design of the plant itself, which is far more important and a far more difficult and complex task.

Parkinson’s Law is the title of a satirical essay by the naval historian C. Northcote Parkinson which was published in The Economist in 1955, following the report of the Royal Commission on the Civil Service. Its notable findings were that:

• Work expands so as to fill the time available for its completion.
• The number of workers within public administration tends to grow, regardless of the amount of work to be done.

The Peter principle states that a person who is competent at their job will earn a promotion to a position that requires different skills. If the promoted person lacks the skills required for the new role, they will be incompetent at the new level, and will not be promoted again. If the person is competent in the new role, they will be promoted again and will continue to be promoted until reaching a level at which they are incompetent.

“Institutions will try to preserve the problem to which they are the solution.” — Clay Shirky

The Shirky Principle declares that complex solutions (like a company, or an industry) can become so dedicated to the problem they are the solution to, that often they inadvertently perpetuate the problem.

The curse of knowledge, also called the curse of expertise or expert’s curse, is a cognitive bias that occurs when a person who has specialized knowledge assumes that others share in that knowledge.

For example, in a classroom setting, teachers may struggle if they cannot put themselves in the position of the student. A knowledgeable professor might no longer remember the difficulties that a student faces when learning a new subject.

The Dunning–Kruger effect is a cognitive bias that describes the systematic tendency of people with low ability in a specific area to give overly positive assessments of their ability. The term may also refer to the tendency of high performers to underestimate their skills.

In popular culture, the Dunning–Kruger effect is sometimes misunderstood as claiming that people with low intelligence are generally overconfident, instead of denoting specific overconfidence of people unskilled in particular areas.

Einstellung […] is the development of a mechanized state of mind. Often called a problem solving set, Einstellung refers to a person’s predisposition to solve a given problem in a specific manner even though better or more appropriate methods of solving the problem exist.

The Einstellung effect is the negative effect of previous experience when solving new problems.

The frequency illusion, also known as the Baader–Meinhof phenomenon, is a cognitive bias in which a person notices a specific concept, word, or product more frequently after recently becoming aware of it.

Hanlon’s razor is an adage or rule of thumb that states, “Never attribute to malice that which is adequately explained by stupidity.” It is a philosophical razor that promotes a way of eliminating unlikely explanations for human behavior, purportedly named after the American writer Robert J. Hanlon, who submitted the statement to Murphy’s Law Book Two: More Reasons Why Things Go Wrong! (1980).

The law of the instrument, law of the hammer, Maslow’s hammer, or golden hammer is a cognitive bias that involves an over-reliance on a familiar tool. Abraham Maslow wrote in 1966, “it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail.”

The philosophical razor advocates that when presented with competing hypotheses about the same prediction and both hypotheses have equal explanatory power, one should prefer the hypothesis that requires the fewest assumptions, and that this is not meant to be a way of choosing between hypotheses that make different predictions. Similarly, in science, Occam’s razor is used as an abductive heuristic in the development of theoretical models rather than as a rigorous arbiter between candidate models.

In philosophy and rhetoric, the principle of charity or charitable interpretation requires interpreting a speaker’s statements in the most rational way possible and, in the case of any argument, considering its best, strongest possible interpretation. In its narrowest sense, the goal of this methodological principle is to avoid attributing irrationality, logical fallacies, or falsehoods to the others’ statements when a coherent, rational interpretation of the statements is available.

In economics and business decision-making, a sunk cost (also known as retrospective cost) is a cost that has already been incurred and cannot be recovered. Sunk costs are contrasted with prospective costs, which are future costs that may be avoided if action is taken. In other words, a sunk cost is a sum paid in the past that should no longer be relevant to decisions about the future.

Sunk costs often influence people’s decisions, with people believing that investments (i.e., sunk costs) justify further expenditures. People demonstrate “a greater tendency to continue an endeavor once an investment in money, effort, or time has been made”. This is the sunk cost fallacy, and such behavior may be described as “throwing good money after bad”, while refusing to succumb to what may be described as “cutting one’s losses”.

The bystander effect (also called bystander apathy or the Genovese effect) is a social psychological theory that states that individuals are less likely to offer help to a victim in the presence of other people.

A 2011 meta-analysis found that the bystander effect was most likely to occur in non-dangerous emergencies but did not occur in dangerous emergencies. The bystander effect was less likely to occur with highly competent bystanders.

The Matthew effect, sometimes called the Matthew principle or cumulative advantage, is the tendency of individuals to accrue social or economic success in proportion to their initial level of popularity, friends, wealth, and natural advantages. It is sometimes summarized by the adage or platitude “the rich get richer and the poor get poorer”.

The tragedy of the commons is the idea that when a resource is shared and can benefit the individual at a cost to the community, it is rational for the individual to overuse the resource, even though this collectively leads to the depletion of the resource for everyone. The concept has been widely discussed and criticized in economics, ecology, and other sciences.

The tyranny of small decisions is a phenomenon in which a number of decisions, individually small and insignificant in size and time perspective, cumulatively result in a larger and significant outcome which is neither optimal nor desired. The concept was first explored in an essay of the same name, published in 1966 by the American economist Alfred E. Kahn. The article describes a situation where a series of small, individually rational decisions can negatively change the context of subsequent choices, even to the point where desired alternatives are irreversibly destroyed.

Berkson’s original illustration involves a retrospective study examining a risk factor for a disease in a statistical sample from a hospital in-patient population. Because samples are taken from a hospital in-patient population, rather than from the general public, this can result in a spurious negative association between the disease and the risk factor.

For example, if the risk factor is diabetes and the disease is cholecystitis, a hospital patient without diabetes is more likely to have cholecystitis than a member of the general population, since the patient must have had some non-diabetes (possibly cholecystitis-causing) reason to enter the hospital in the first place. That result will be obtained regardless of whether there is any association between diabetes and cholecystitis in the general population.

The Pareto principle (also known as the 80:20 rule, the law of the vital few and the principle of factor sparsity) states that, for many outcomes, roughly 80% of consequences come from 20% of causes (the “vital few”).

Survivorship bias or survivor bias is a statistical error which results from concentrating on entities that passed a selection process over those that did not. This can lead to incorrect conclusions because of incomplete data.

Survivorship bias may lead to overly optimistic beliefs because multiple failures are overlooked, such as when companies that no longer exist are excluded from analyses of financial performance.

1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
3. Any sufficiently advanced technology is indistinguishable from magic.

With a sufficient number of users of an API, it does not matter what you promise in the contract: all observable behaviors of your system will be depended on by somebody.