How close can indents be placed without risking an erroneous pop-in statistics?

Load-displacement curves with spherical indenters often exhibit a so-called pop-in, which can be interpreted as elastic-plastic transition due to activation or even nucleation of dislocation sources. Due to the stochastic nature of deformation at the micron scale a wide distribution of pop-in loads (referred as pop-in statistics) can be observed. This work presents the critical distance at which a mutual interaction of dislocations from two indents can be excluded. It is found that the critical distance strongly depends on the material. A quantitative model for estimating the critical distance is provided, which might serve an experimentalist as a guideline for planning reliable experiments.