The HCI Compensation Tool uses a Point Table system to evaluate Jobs. The levels created for each sub factor should represent a distinct level (seniority, ability, skill etc...) in your organization and thus allow for placement of each job at a level. For some factors it is more challenging to decide between 2 levels of a sub factor as the job has aspects of both levels and thus the ability to select half levels is provided and employed. Note: In some cases the levels can be very exact (for example, experience) and thus may not require the ability to select between 2 levels, thus explicit half levels are used.
If you require the ability to select smaller increments than 0.5, your Point table is probably either too complicated for use in the HCI Compensation Tool, or your sub factors levels have not been created properly with enough / too much distinction between levels. If your existing Point Table requires smaller increments than 0.5, you may be able to play with the weighting and levels to achieve desired results, please contact a consultant at HCI if you would like to discuss options.
If your Point Table does not use half point (0.5) increments, you can simply ignore them in the Point Table and Evaluations (although the ability still exists).