the use of blind or double-blind investigators in a study is done to avoid:
sampling error.
sample bias.
uncontrollable variables.
researcher bias.
random error.
i think it is researcher bias
Didn't you understand bobpursley's answer?
https://www.jiskha.com/questions/1774701/The-use-of-blind-or-double-blind-investigators-in-a-study-is-done-to-avoid-sampling
Possibly you might understand this explanation.
1. Single blind gives the control group a placebo — a substance that is inert, it has no physical effect. Subjects don't know if they are in experimental or control group to reduce placebo effect, a change in behavior solely due to believing that you are getting the independent variable.
2. Double blind keeps both subjects and experimenter ignorant of group setup. Distribution of the independent variable and placebo are controlled by third party. This controls for experimenter bias and self-fulfilling prophecy, which means that experimenters with particular expectations are likely to consciously or unconsciously to bias the experiment and influence it to conform to their expectations.
You are correct! The use of blind or double-blind investigators in a study is done primarily to minimize researcher bias. Researcher bias refers to the unconscious or conscious influence of the researcher's own beliefs, expectations, or preferences on the outcome of a study. It can occur when researchers unintentionally influence the results or interpretation of a study due to their knowledge or involvement in the research process.
By employing blind or double-blind investigators, the researchers are prevented from consciously or unconsciously influencing the study outcomes. Let's briefly explain the other options you mentioned:
1. Sampling error: This refers to the discrepancy or variation that occurs when the sample used in a study differs from the target population. It is not specifically addressed by using blind or double-blind investigators.
2. Sample bias: This occurs when the sample chosen for a study is not representative of the target population, leading to skewed or inaccurate results. While blind or double-blind investigators can indirectly help reduce sample bias, their primary purpose is to minimize researcher bias.
3. Uncontrollable variables: These are factors that cannot be manipulated or controlled by the researcher, such as natural environmental conditions or inherent differences among individuals. Blind or double-blind investigators do not directly address uncontrollable variables.
4. Random error: This type of error refers to natural variability in measurements and observations. Blind or double-blind investigators are not primarily used to reduce random error, but rather to minimize the potential bias introduced by the researchers.
In conclusion, the primary purpose of using blind or double-blind investigators in a study is to avoid researcher bias.