Definition: Multifactoral reasoning

Multifactoral reasoning is reasoning in which there are many factors to be considered, or to be weighed, in arriving at a proper conclusion.

For example, if someone is hiring to fill a single position from a pool of applicants, there is likely to be multifactoral reasoning involved. Each applicant will be assessed with regard to several qualifications, such as experience, personality, education, demonstrated skills, reference letters and availability. Since each applicant will have some strengths and some drawbacks, an overall appraisal must be made which weighs together the many factors for each person, and arrives at a conclusion as to which person is best suited to the job, if any. So that would be a case of multifactoral reasoning.

Or, to take another example, a judge (or member of a jury) in a criminal trial will usually be involved in multifactoral reasoning in arriving at a conclusion which finds a defendant guilty or not guilty. Very frequently, the prosecuting or petitioner's lawyer and the defendant's lawyer will raise at least some pro and con factors which must be weighed carefully in arriving at a conclusion.

There are many situations in which we use multifactoral reasoning, as one can see from these two cases.

Here is a format within which multifactoral reasoning can be done. The format is meant as an introduction to multifactoral reasoning.

Step 1

Articulate the different possible conclusions one might reach. For example, if the decision to be made is the hiring of someone, and a shortlist has already been constructed, the possible conclusions might be: Possible conclusion #1: Green is the best applicant for the job and the job should be offered to her; Possible conclusion #2: Blue is the best applicant for the job and the job should be offered to him; Possible conclusion #3: Black is the best applicant for the job and the job should be offered to her; Possible conclusion #4: We must continue searching, as none of the shortlisted candidates are quite right.

Step 2

Present the background and recent evidence at hand which appears to be at least potentially relevant to the discussion (Eg., in this case, letters of reference, interview summaries, etc.).

Step 3

Determine all the factors which are pro each potential conclusion. And determine all the factors which are con each potential conclusion. Make a table which lists all the pros for each possible conclusion, and the cons for each possible conclusion.

Step 4

Check for comprehensiveness. Search for other relevant factors that have not been included in the pros and cons list.

Step 5

Weigh the pros and the cons in terms of their importance. (The techniques for weighing are highly specific to the specific case examples and example types. There are about 10 or so main categories of reasoning situations, and for each one there are specific issues to consider in regard to appropriate weighing of factors for that type of reasoning.)

Step 6

Establish the direction of the conclusion, and the considerations (if any) which prevent one from making a flat-out unqualified assertion of the conclusion. In this case, suppose that the weighing of evidence of Step 5, favours possible conclusion #1, Green is the best of the applicants, and the job should be offered to her. However, one of the letters of reference is either missing from the file or has not come in. Then, in Step 6, one might add the condition onto possible conclusion #1, Subject to the missing letter of reference being found or received, and it being satisfactory.

Step 7

Assert the conclusion with the qualifications or conditions added, if any, in Step 6. For example, the conclusion might be: Green is the best of the applicants and the job should be offered to her, as long as the missing letter of reference is found or received first, and the reference is satisfactory.


This page on multifactoral reasoning, and the format, were prepared by Douglas College Philosophy instructor Leonard Angel. For further information on multifactoral reasoning and the "six virtues approach to critical thinking," contact Leonard at or call 604 527 5201.