How do people choose a number on a scale?

The range-frequency model indicates that each numbered answer receives a an equal proportion of responses.

Departures from the range-frequency model

• Positivity bias --- people do not like to rate low
• Scale labels effects --- negative numbers seem too extreme
• Response contraction bias --- values at extremes receive few responses
• Reference point effects --- do some numbers have particular meaning?

Source: Tourangeau, R., Rips, L. J., Rasinksi, R. (2000). The Psychology of Survey Response. Cambridge, UK: Cambridge University Press.