Research methods

A correlation coefficient of -0.85 indicates a strong negative relationship because the value is close to -1.0, meaning that as one variable increases, the other decreases. Option D is incorrect because correlation only demonstrates a relationship between variables and cannot establish causation. Option A would require a positive sign.

Peer review ensures that independent experts in the same field critically evaluate the research methodology and findings before publication, which increases the study's overall credibility. Option A is incorrect because peer review cannot guarantee absolute truth or error-free results, but rather acts as a quality control filter.

A correlation coefficient of -0.85 indicates a strong negative relationship because the value is close to -1.0, meaning that as one variable increases, the other decreases. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.

• !Option D is incorrect because correlation only demonstrates a relationship between variables and cannot establish causation.
• !Option A is incorrect because peer review cannot guarantee absolute truth or error-free results, but rather acts as a quality control filter.
• !Option A is incorrect because predicting an expected difference is the role of an alternative or research hypothesis, which the null hypothesis directly opposes.

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