In this study I explore children's working knowledge of narrative, scientif
ic, and poetic genres. Fifty-four kindergarten,first-grade, and second-grad
e children composed original texts representing each of these genres. They
also provided oral justifications for why each of their texts instantiated
the designated genre. All texts were coded for the presence or absence of a
variety of textual and structural features that are typically distributed
differentially across the three focal genres. Analyses showed that particip
ants had significantly more experience with narrative genres than either sc
ientific or poetic genres and that they possessed significantly more workin
g knowledge of narrative genres than the other focal genres. Additionally p
articipants possessed move knowledge of macro-level genre features stich as
text structure than micro-level features such as cohesion markers. The fin
dings suggest that children develop increasingly differentiated and flexibl
e repertoires of genre forms and functions. Comparing findings from this st
udy with findings from other studies suggests that tasks and task contexts
significantly influence how and to what extent children demonstrate their g
enre knowledge, that different tasks scaffold genre learning in different w
ays and to different degrees, and that children's imbalanced exposure to di
fferent genres may contribute to their differential knowledge of genres. Th
e study contributes to theorizing genre learning as a complex, contingent,
and emergent process of differentiation and integration.