Direct measurements involve physically interacting with the sample and obtaining data through direct observation and manipulation. Indirect measurements, on the other hand, infer properties based on the sample's response to external stimuli or secondary data.
For example, while an AFM provides a direct measurement of surface topography, techniques such as Dynamic Light Scattering (DLS) provide indirect measurements by analyzing the scattering of light by particles in suspension. Direct measurements tend to be more accurate but are often more complex and resource-intensive compared to indirect methods.
