### Instruction:

Extract the cause and effect entities from the following sentence:
Requirement: in case of the presence of clusters of bad pixels invalidating the dithering require- ment 4.5.1.5, the planned scanning strategy or the field observing sequence shall be modified

### Assistant:

NOT_RELEVANT: Requirement:
KEYWORD: in case of
VARIABLE: the field observing sequence
CONDITION: shall be modified
CAUSE_1: the presence of clusters of bad pixels invalidating the dithering require- ment 4.5.1.5
OR: or
EFFECT_1: the planned scanning strategy
EFFECT_2: the field observing sequence shall be modified

