In the NOS election debates for the Dutch General election, 2017, invited parties include all 11 parties that gained seats at the previous elections as well as the new parties Nieuwe Wegen, VoorNederland, and DENK. How are the latter three invitees determined? In polls, DENK polls at 0–2 seats, VoorNederland at 0–1 seats, and Forum voor Democratie at 0–1 seats. Forum voor Democratie was not invited; Nieuwe Wegen was; I have not seen any opinion poll in which it would enter parliament (threshold 0.67%). The linked NOS article states invitees are voor de helft bepaald door het huidige aantal zetels in de Tweede Kamer en voor de andere helft door de Peilingwijzer van 1 februari, which means determined half by the current seat number in de Tweede Kamer and half for the other by the meta-poll Peilingwĳzer. However, neither Nieuwe Wegen, VoorNederland, or DENK are currently in parliament, and Nieuwe Wegen has not even appeared in Peilingwĳzer, so that does not explain why Nieuwe Wegen was invited but Forum voor Democratie was not.
Based on what criteria does NOS decide what 14 parties to invite to the election debate?