INFERENCE PATH

Dr. David Hitchcock, Professor of Philosophy at McMaster University, presents, on page 8, a representative example of conventional argument mapping using an argument from Plato. The ADEPT™ Inference Path argument map illustrates an alternative depiction of the argument using more premises for the purpose of increased clarity.

Dr. Douglas Walton presents an excellent explanation of the scheme for argument from expert opinion. The recent article suggests many more assumptions than have previously been presented. Translating the scheme into an ADEPT™ Inference Path helps to, perhaps, more definitively distinguish between the “ordinary premises” (i.e., stepping stones) and the supporting assumptions. And this structure indicates which specific ordinary premise is supported by the assumptions.

Austhink provides, at page 26, an effective example of creating a nonsensical argument using greeking to illustrate the scaffolding of conventional argument mapping. The following Rationale™ argument map is illustrative.

The visual grammar of conventional argument mapping does an excellent job of organizing the components of an argument. This process removes much of the confusion that can result from inadequate signal words or a lack of clear structure in the prose separating reasons from the conclusion. There is, however, a significant deficiency in this scaffolding.

As the above example illustrates, the scaffolding of conventional argument mapping permits a nonsensical or structurally fallacious argument. Students can just put nonsense in the boxes and satisfy the visual grammar. Why not have the visual grammar permit only structurally valid arguments in the first place. An ADEPT™ Inference Path argument map accomplishes this goal through its transitive linking of the premises as illustrated below in the two argument maps.

Dr. Jerome Groopman, chief of experimental medicine at Beth Israel Deaconess Medical Center in Boston, describes many of the possible cognitive errors that can occur in clinical practice in his excellent recent book, How Doctors Think. These cognitive errors can be depicted as supporting assumptions (i.e., answers to “critical questions”).

The ADEPT™ argument map illustrates that a very slender reed can support the premises that lead to a diagnosis. The removal of any one of the supporting assumptions would cause the inference path to collapse removing any chance of any level of certainty or acceptability reaching the conclusion along this particular inference path. Of course, there could be other inference paths that lead to this conclusion which have sufficient probative strength.

Perhaps cognitive errors should be added to the list of the six standard critical questions for Argument from Expert Opinion created by Dr. Douglas Walton.

The U.S. Supreme Court heard, on December 3, 2007, a job-related age discrimination case in which the Justices questioned the relevance of “me too” evidence. http://www.nytimes.com/2007/12/04/washington/04scotus.html?_r=3&adxnnl=1&oref=slogin&adxnnlx=1197252263-sjRNGwGwkDPcErysWFi9WA&oref=slogin. The Justices’ apparent objections to plaintiff’s argument of relevancy are depicted below in an ADEPT™ Inference Path argument map. Depending on the strength attached to the objections, the Justices may not reach plaintiff’s conclusion.