Argument by example

In an argument by example, the premises are specific instances that are used to lead to a general conclusion.

It is a form of inductive reasoning where a sample is used as the basis for a generalisation about a larger set of the same thing. This movement from specific to general is a common mental process and it can feel reassuring when we find patterns. It becomes easier to interact with the world if we reach some general conclusions about things and experiences.

There are essentially two things that are important in a strong argument by example. It comes down to the quantity and quality of the examples.

QUANTITY OF EXAMPLES
Use more than one example. One example does not provide a sound basis. It is not a sample, it is just a specific instance. The number of examples depends on the size of the set you are making a generalisation about. The larger the set of things being considered the greater the number of examples that should be reviewed.

QUALITY OF EXAMPLES
But the size of the sample is not as important as whether the sample provides a meaningful and accurate representation of the total set. Otherwise you have a biased sample. Here you run into complex issues about how to identify and access a representative cross section.

One methodology is to use a random sample. This is not the same thing as a haphazard sample. It requires detailed planning and thought. First, the sample needs to come from the entire group- and this may take some digging before the entirety of the group can be revealed. For example, the set of “Europeans” would have to first define what the term means. Does it include people born in a European country but now living overseas, and does it include people born outside a European country who have acquired European citizenship in their lifetime, or who live in Europe under some form of temporary residence?

Second, identify all, or as many as possible, of the categories or characteristics of the items or things coming with the defined term. For example, in an argument looking at Europeans, just some of the characteristics to represent within the sample set would include gender, social-economic background, level of education, age, employment status, urban or rural habitat.

Third, the proportion of each grouping used in the sample should reflect the proportion of each grouping within the entire set. Every member of each group should have an equal chance of being included in the sample.

NATURE OF THE ARGUMENT
Often, arguments by example are weak and can rightly be frowned upon. It only requires one counterexample to overturn the conclusion- unless the conclusion was appropriately qualified.

It is difficult to construct a broadly convincing cross section that is accurately representative of the whole. Some steps that might be used in a methodology to reach an accurate sample were outlined above. Each step is difficult and requires careful thought- the strength of the argument is reliant on how skillfully the arguer constructs a meaningfully representative sample on which the generalisation is based.

Apart from that, arguments by example are troubling for their propensity to be found in arguments used racists or bigots. Statements that make sweeping generalisations about groups of people are expressions of prejudice, rather than arguments.