Final answer:
The actual van't Hoff factor is usually less than the ideal van't Hoff factor.
Step-by-step explanation:
When comparing the ideal van't Hoff factor to the actual van't Hoff factor, the actual van't Hoff factor is usually less than the ideal van't Hoff factor. The ideal van't Hoff factor is what we expect from the ionic formula, but at concentrations greater than 0.001 M, there are enough interactions between ions of opposite charge that the net concentration of the ions is less than expected. This results in the actual van't Hoff factor being less than the ideal one.