The Six Types of Valid Anecdote

The plural of anecdote is data. An anecdote to ignorance or absence is not.

Many of us are familiar with the misquote attributed to Wolfinger, stating that “The plural of anecdote is not data.” However, this commonly repeated trope of social skepticism is actually incorrect. In reality, there are certain types of anecdotes that can be considered as data, information, or even intelligence.1 There are six circumstances in which a single anecdote holds valid inferential significance – yes, even if it involves personal testimony. It is important to recognize that skeptics who dismiss all forms of anecdotal evidence, except for one particular invalid application cited in strikethrough below, are using a deceptive tactic. This deceptive tactic is akin to a magician’s trick – the anecdotal appeal to ignorance or absence.2

Six Types of Valid Anecdote (and Two Invalid but Popular Types)

1. White Crow

In a laboratory, it is assumed that a specific material state is either non-existent or unachievable. Instead of accepting this null hypothesis, the laboratory engages in a seemingly impractical process of systematically testing every possible combination of experimental conditions in order to bring about this desired material state. After six weeks of exhaustive testing, they finally discover a particular set of control conditions that successfully produces the sought-after material state. As a result, the null hypothesis has been proven false.

2. Negation of a Claim to Scarcity

A wildlife team receives information suggesting that the population of a specific horse breed in a particular island nation is extremely scarce. Tasked with the job of assessing that horse population, they embark on an expedition with the intention of counting these horses. Surprisingly, within mere minutes of commencing their first random sampling run, they come across the first herd of the target horse breed. One looks for a needle in a large haystack, and finds a needle upon first glance. Intelligent life on Earth.

3. When Testing Policy or Constraint

After being a loyal customer for ten years with no claims, your insurance company unexpectedly raises the rates on your homeowner’s insurance by a significant 20+% for the third consecutive year. Perplexed by this substantial rate increase, you decide to call and inquire about the reason behind it. During the conversation, the agent attributes the steep rise in costs to “roof replacement fraud” plaguing the insurance industry. In order to validate this claim, you request the insurer to assess the extensive hail damage affecting your aging roof. Following their longstanding policy, the insurer sends their own evaluation team to examine your roof. Their evaluation results in a credit of $1,600 for the hail damage, which falls below your deductible. As a result, you are left with the burden of covering the entire cost of the roof replacement, amounting to $16,000. It becomes evident that the insurer has misrepresented the reasons for their cost increases, as their policy prevents them from assuming such liabilities.

4. Small Relevant Domain

You observe a person drinking in a bar, and make the claim that you are more likely to find a buzzed or drunk person in a bar, as compared to other public venues.

5. Case Study During Discovery/Profiling

A person suffering long-term infection by Epstein-Barr virus is found to have Hodgkin’s lymphoma later in life. The diagnosing physician suspects a connection, and wishes to document it in a case study. A suspect in a robbery has his background checked, whereupon his criminal history is found to contain two convictions for petty theft.

6. As a Datum to the Presence (the plural of which is data)

Personal testimony that a popular brand of dimmable light switches installed in a house caught fire through overheating. Your new phone suffers a hardware malfunction right after you purchase it. You observe a thylacine crossing your farmyard to chase after your barn cat.

7. As a Datum to the Absence (anecdotal appeal to ignorance)

Your friend’s house with dimmable light switches installed did not burn down. Your grandfather lived to age 92 after smoking his entire life. You had the Covid vaccine and are fine.

8. As a Data Set to the Absence (utile absentia – appeal to failure in detection/collection)

You conduct a study on house fires, in order to see if houses with dimmable light switches suffer a higher proportion of fires. However, newer house fire incidents have yet to be entered in many district fire department databases. As well, newer houses tend to have a greater number of dimmable light switches installed. Amazingly, houses with dimmable light switches are found to rarely have fire incidents. Most house fires collected into your database therefore occur in houses with conventional flip switches. Your report concludes that dimmable light switches do not cause more house fires as compared to conventional ones. Moreover, although not acknowledged inside your conclusions, the data shows that dimmable light switches actually prevent all unrelated forms of house fire as well (inversion effect indicative of a utile absentia exclusion error).

Be cautious of individuals who clumsily twist Wolfinger’s misquote or assert that your personal experience holds no value as “evidence.” They might be spreading misleading philosophy. If they habitually commit appeal to absence errors, numbers 7 and 8 above in particular, it is certainly wise to avoid seeking their advice regarding skepticism or science.

The Ethical Skeptic, “The Six Valid Types of Anecdote”; The Ethical Skeptic, WordPress, 24 Jun 2023; Web,