Table 1

Conceptual complexity dimension levels
Level
 Format given before choice:
 Range restriction? (numbers 1–5 only)
 Dot fading present? (duration)
 Hazards present?
 Addition required?
 Subtraction required?
 Instructional goal








Non-symbolic (dot clouds)
 Symbolic: Verbal (spoken numbers)
 Symbolic: Arabic (digits)





1
 Yes
 No
 No
 Yes
 No
 No
 No
 No
 Attention to and processing of small non-symbolic quantities
2
 Yes
 No
 No
 No
 No
 No
 No
 No
 Attention to and processing of large non-symbolic quantities
3
 Yes
 Yes
 Yes
 Yes
 No
 No
 No
 No
 Link small non-symbolic quantities to symbolic codes
4
 Yes
 Yes
 Yes
 No
 No
 No
 No
 No
 Link large non-symbolic quantities to symbolic codes
5
 Yes
 Yes
 Yes
 No
 Yes (4 sec)
 No
 No
 No
 Increase reliance on symbolic codes
6
 Yes
 Yes
 Yes
 No
 Yes (1 sec)
 No
 No
 No
 Further increase reliance on symbolic codes
7
 No
 Yes
 Yes
 No
 No
 No
 No
 No
 Require complete reliance on symbolic codes
8
 No
 No
 Yes
 No
 No
 No
 No
 No
 Require complete reliance on Arabic code
9
 No
 No
 Yes
 No
 No
 Yes
 No
 No
 Attention towards exact quantity
10
 No
 No
 Yes
 Yes
 No
 Yes
 Yes
 No
 Comprehension and fluency of small addition problems
11
 No
 No
 Yes
 No
 No
 Yes
 Yes
 No
 Comprehension and fluency of larger addition problems
12
 No
 No
 Yes
 Yes
 No
 Yes
 No
 Yes
 Comprehension and fluency of small subtraction problems
13
 No
 No
 Yes
 No
 No
 Yes
 No
 Yes
 Comprehension and fluency of larger subtraction problems
14
 No
 No
 Yes
 No
 No
 Yes
 Yes
 Yes
 Distinguishing between addition and subtraction

Notes.

"Range restriction" means that the range of quantities presented was from 1–5.

"Dot fading" means that the collections of gold pieces were faded from view in the space of either 1 or 4 seconds, gradually helping to introduce a reliance on symbolic codes.

"Hazards" means that there were new anemone hazards placed on the game board, which children had to try and avoid, encouraging a focus on exact quantity

In addition trials, instead of presenting a simple quantity, an addition problem with a sum of up to 9 was presented on one side of the screen.

In subtraction trials, the problems had operands of 9 or below, and thus a result of 8 or below.

Wilson et al. Behavioral and Brain Functions 2006 2:19   doi:10.1186/1744-9081-2-19