De or het effectbeoordeling?

The correct Dutch article is:

de effectbeoordeling

Rule Words ending in -ing: almost always de. See the rule

How to use effectbeoordeling

the effectbeoordelingde effectbeoordeling
this effectbeoordelingdeze effectbeoordeling
that effectbeoordelingdie effectbeoordeling
our effectbeoordelingonze effectbeoordeling
your effectbeoordelingjouw effectbeoordeling
every effectbeoordelingelke effectbeoordeling
which effectbeoordeling?welke effectbeoordeling?
a big effectbeoordeling / the big effectbeoordelingeen grote effectbeoordeling, de grote effectbeoordeling

Dutch words ending in effectbeoordeling

milieueffectbeoordeling

In compound words, the last part decides the article. See the rule