The following model uses 'block of time' costing to estimate the cost of reference services. This model resembles an Excel spreadsheet because it's derived from one using a commercially produced Excel plug-in called "ExcelEverywhere." The blue cells in the spreadsheet can be manipulated by you. So, take it for a spin!

It's important to note that 'block of time' costing does not account for the ability of the digital reference librarian to multitask. Most librarians feel that this grossly overestimates the labor costs of most reference services (especially a synchronous digital reference service. It's especially troubling with low traffic situations. Note that the default "Reference transactions per month" is 55. Also note the large dollar amount given for the cost per reference transaction. Now use the model to change the 55 to ... perhaps 220 reference transactions per month. Note that costs overall appears to stay the same, but the cost per reference transaction will drop dramatically. For a better model that takes "idle time" into account see http://www.contrib.andrew.cmu.edu/~matthewm/vrd2003/DigRefCostModel.html.

Single Library Digital Reference Cost Model        
      Cost per Hour per Senior Librarian 31
Number of Digital Reference Service Points   Cost per Hour per Librarian 24
Number of Hours of Service per Week (B4)   Cost per Hour per Grad Student 7.5
Number of Hours Provided by Senior Librarians per Week (B5)   Cost of Software per Year per Seat
Number of Hours Provided by Librarians per Week (B6)   Cost of Software per year
Number of Hours Provided by Grad Students per Week (B7)   Cost of Software per week
Reference Transactions Per Month      
Reference Transactions Per Hour      
         
Cost of Labor Per Week      
Cost Per Service Hour      
Cost of Labor Per Year (minus holidays and breaks)      
Cost Per Year (minus holidays and breaks)      
Cost per Reference Transaction      
         
Instructions: Alter the numbers in the blue cells. Make sure that B5, B6 and B7 add up to B4.        

Automatic recalculation