$2$a$.$ Illustrate at least five processes model of prototyping that can be used to solidify the process $(15$ marks$).$

$2$b$.$ Differentiate between the followings:

$2$b$.$ i$.$ An interaction perspective, $(4$ marks$)$

$2$b$.$ ii$.$ external perspective, $(4$ marks$)$

$2$b$.$ iii. structure perspective. $(4$ marks$)$

$2$b$.$ iv$.$ behavioural perspective