11.4 Quick revision questions

A study on the bruising of apples (Doosti-Irani et al. 2016) aimed to determine the relationship between the recorded surface temperature of apple, the depth of bruising.

The researchers purposefully hit apples with three different forces (200, 700 and 1200 mJ) to inflict bruises.

This was repeated at three different locations of the apple (lower; middle; upper).

The researchers then recorded the depth of the bruising, and recorded the surface temperature at each bruise location.

  1. How would the variable ‘region of the apple’ be best described?
  2. How would the variable ‘depth of bruising?’ be best described
  3. How would the variable ‘temperature of the bruise location’ be best described?
  4. The variable ‘force of hit’ could be considered as quantitative continuous variable. However, since only a small number of forces are used, it could also be considered as qualitative ordinal.
    If it was considered as qualitative ordinal, how many levels would the variable have?


Doosti-Irani O, Golzarian MR, Aghkhani MH, Sadrnia H, Doosti-Irani M. Development of multiple regression model to estimate the apple’s bruise depth using thermal maps. Postharvest Biology and Technology. Elsevier; 2016;116:75–9.