Factors determining the clinical usefulness:
(1) relevance/applicability of the information to the problem
(2) validity/reliability of the information
(3) time, work and cost to access and use the information
The authors used these in an equation, but this may be simply indicate the relative relationships between the factors:
usefulness = (relevance) * (validity) / (cost and work to access)
In some ways this is a cost-benefit analysis.
Smith added a factor for the ability to interact with the information source. This not only helps to determine the validity of the information (thereby increasing user confidence), but also helps a person unfamiliar with a problem have questions answered and issues clarified. This helps reduce the work required by the user to understand the material.
For the implementation I will score each item on a 4 point Likert scale scored 0 to 3, then add the values. An ideal information source would have a maximal score of 9. Alternative ways to handle the data would be to make the score exponential and to multiply the values.
