### Instructions for Ratios of Darkness

Your task is to judge the ratio of darkness between each pair of dot patterns. Each judgment is like a division problem, judging the darkness on the left divided by the darkness on the right. Estimate your ratios expressed as percentages, as in the following examples:

12.5= pattern on the LEFT is 1/8 as dark as pattern on the RIGHT

25 = pattern on the LEFT is 1/4 as dark as pattern on the RIGHT

50 = pattern on the LEFT is 1/2 as dark as pattern on the RIGHT

100 = pattern on the LEFT is equally as dark as pattern on the RIGHT

200 = pattern on the LEFT is twice as dark as pattern on the RIGHT

400 = pattern on the LEFT is four times as dark as pattern on the RIGHT

800 = pattern on the LEFT is eight times as dark as pattern on the RIGHT

You may use any numbers, in between or more extreme than the above examples, to express your estimations of ratios of darkness.

#### Warmup Trials for Ratios of Darkness

Please re-read the instructions, then continue with the items below.