In experimental research, which of the following can have its possible effects controlled by blind and double-blind procedures?
Select one: a. confounding variables b. high costs c. expectations d. chance factors
The correct answer and explanation is:
The correct answer is: c. expectations
In experimental research, blind and double-blind procedures are primarily designed to control the effects of expectations, both from participants and experimenters. These procedures aim to reduce biases that may arise from conscious or unconscious expectations influencing the outcomes of the study.
Blind procedures:
A blind procedure refers to the practice where participants are unaware of certain key aspects of the experiment. For example, they might not know whether they are receiving the experimental treatment or a placebo. This helps to control for participant expectancy, also called the placebo effect, where participants’ expectations about the treatment can influence their perception of the outcome, regardless of the actual treatment’s efficacy.
Double-blind procedures:
A double-blind procedure takes this a step further by also ensuring that the researchers or experimenters conducting the study are unaware of which participants are in the treatment or control groups. This eliminates any experimenter expectancy bias, where the experimenter’s expectations might subtly influence how they interact with participants, interpret data, or even measure results.
Both procedures aim to ensure that expectations—whether from the participant or the researcher—do not interfere with the results. By keeping both parties “blind” to the experimental conditions, any differences observed in the results can be attributed to the experimental manipulation itself, rather than biases.
Why the other options are not correct:
- a. Confounding variables: While blind and double-blind procedures help to reduce certain types of bias, they do not directly control for confounding variables. These are external factors that could affect the dependent variable and are typically controlled through random assignment, matching, or statistical control.
- b. High costs: Blind and double-blind procedures do not impact the cost of the research. The cost factors are usually related to the resources required for data collection, equipment, and analysis.
- d. Chance factors: Chance or random error is inherent in any study, and while these procedures help reduce bias, they cannot fully control for random fluctuations in data.
In conclusion, blind and double-blind procedures are critical for reducing the effects of expectations on experimental outcomes, ensuring the research findings are as objective and unbiased as possible.