Overall score for the Blueair Classic 605 is mainly how well the model removed dust and smoke from a test chamber, plus quietness for room purifiers.
Dust/pollen/smoke removal: How well models cleared air of fine clay dust and cigarette smoke; performance of portables is at their highest and lowest speeds. Ones that scored well for dust removal should perform comparably for pollen.
Noise: Based on instrument measurements with a portable model running at its highest and lowest speeds.