Would this kind of paraphrasing be called "plagiarism"? Original Text:

The questionnaire was designed by the researcher to gather data on the
perceptions of students based on their experiences in the blended
environment. It consisted of Likert-type items and open-ended
questions. The content of the questionnaire was derived from a
literature review on blended learning and authenticity of learning,
from conversations with teaching staff, and from the researcher‟s
previous experiences in the use of blended format in teaching and
learning. Experts from Doctoral Committee were asked their opinions in
order to ensure content validity.

My Text
This part will be readded after finalizing my thesis.
Assuming that (Gedik, 2010) is the source of the original, I don't think you have a problem since, (a) you give the citation and (b) the ways to express the needed ideas here are very limited.
You are clearly making reference to the original work. And it is clear you are describing the work of another.
The essential elements describing the questionnaire must all be present and you have minimally done that.