Why was an unrepresentative survey carried out by the National LGBT Federation?

"While the number of participants was relatively large, they were not a random sample of the overall national population so the results may not be representative...Any follow-up to this study should use a representative sampling approach to overcome these limitations."

Why was an unrepresentative survey carried out by the National LGBT Federation?

Thread from 3rd March 2022

A representative sample of 1,001 adults were asked their views on a range of gender-related issues by the RedC company.

Women have a view on men being able to identify as women: please include us in the debate.

Irish Public Have Say in First Irish Gender Poll
Irish society has become more accepting of gender expression, but when it comes to the provision of intimate spaces and services, biological sex matters. The Countess last month commissioned the first…
https://thecountess.ie/first-irish-public-poll-on-gender-debate/

Podcast from Tuesday on the new National LGBT Federation survey funded by the US Tides Foundation:      

Some interesting comments carried in the report:    

NXF-Across-the-Spectrum.pdf
from the report, page 39

Qualification added to the survey results:  

from the report, page 54

Given that this initiative was funded by the US Tides Foundation, why was a study asking a representative sample of the Irish population not commissioned in the first place?