The purpose of a double-blind study is to:

a. achieve comparability of cases and controls.
b. reduce the effects of sampling variation.
c. avoid observer and interviewee bias.
d. avoid observer bias and sampling variation.
e. avoid interviewee bias and sampling variation.

C. avoid observer and interviewee bias.

Explanation:

I

Double blind type is a type of clinical trial in which neither the observer nor the interviewee team

knows the treatment type to be administered to a m specific

participant is receiving. This helps prevent bias or expectations from influencing the results of the study.

hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.

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