17. Lee’s Migration Model
Location A Location B
Intervening Obstacles
+ - + -
0 Intervening Place 0
18. Lee’s Migration Model
Location A Location B
Intervening Obstacles
+ - + -
0 Intervening Place 0
+ -
0
19. Lee’s Migration Model
Location A Location B
Intervening Obstacles
+ - + -
0 Intervening Place 0
?
+ -
0
20. Lee’s Migration Model
Location A Location B
Intervening Obstacles
+ - + -
0 Intervening Place 0
?
+ -
0
Source: Adapted from Global Challenge. Alistair McNaught and Michael Witherick. Longman. 2001.