### 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 two times 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

W1. / (These two are equal, so you respond "100".)

W2. / (These two are also equal.)

W3. / (Which is darker? What is the ratio of LEFT divided by RIGHT?)

W4. / (Which is darker? Judge ratio of LEFT to RIGHT)

W5. /

W6. /

W7. /

W8. /

1. /

2. /

3. /

4. /

5. /

6. /

7. /

8. /

9. /

10. /

11. /

12. /

13. /

14. /

15. /

16. /

17. /

18. /

19. /

20. /

21. /

22. /

23. /

24. /

25. /

26. /

27. /

28. /

29. /

30. /

31. /

32. /

33. /

34. /

35. /

36. /

37. /

38. /

39. /

40. /

41. /

42. /

43. /

44. /

45. /

46. /

47. /

48. /

49. /

50. What is your age? years.
51. Gender: Are you Male or Female?
Female
Male

52. How many years of Education have you completed? Put 12 for High School Diploma
Put 16 for college diploma (bachelor's degree).
put 20 for doctorate degree (Ph.D., M.D., etc).
Education:
53. Nationality (country of birth):