These words refer to an aimless, irregular or erratic procedure. Random suggests something arrived at through accident or through arbitrary choices; it implies lack of specific direction or intent: a random gathering of friends and acquaintances; The followed a seemingly random track through the bush; having random thoughts on ways to redecorate her flat.

Casual points to something that happens without intention or plan and may give a sense of freedom and ease: a casual meeting on the street; a casual question; a casual stroll on the lawn. On the other hand, it may also suggest the qualities of indifference or unconcern: a casual handshake; showing by his casual manner that he was unaffected by their plight.

Desultory stresses a procedure marked by stops and starts but includes the lack of plan implied by random and the lack of formality implied by casual : the desult ory talk of old friends interrupted by lapses and long silences. Less favoruably, the word can suggest wandering attention, instability or inconsistency: his desultory attempts to keep his correspondence up to date. Haphazard is even stronger in negative implications than desultory ; it is used almost exclusively in a disapproving way for unsystematic work or behaviour that is indifferent to accuracy and efficiency: haphazard and slapdash experiments on which no sound conclusion can be based.