Introduction to the Process of Science: Study Guide

Standard Process: Follows a specific order: observation, question, scientific hypothesis, experiments, data collection, and conclusions.
Hypothesis Criteria: Must be both testable (can be supported or rejected by data) and falsifiable (can be proven wrong).
Hypothesis vs. Theory: In science, a scientific theory is an explanation supported by a large body of evidence, whereas the everyday use of "theory" implies a mere hunch or guess.
Peer Review: A rigorous process where external experts evaluate a study's design and results before it is published in a journal to ensure validity.

Controlled Experiment: Includes at least two groups to isolate the effects of a single factor.
Experimental Group: The group receiving the specific treatment or intervention under investigation.
Control Group: The group receiving a placebo (an inactive treatment like colored water) to provide a baseline for comparison.
Independent Variable: The factor being deliberately changed or manipulated by the researcher (e.g., the amount of caffeine or radiation).
Dependent Variable: The measured result or outcome of the experiment (e.g., test scores or cancer incidence).
Randomization: Participants should be assigned to groups randomly to ensure that both groups are as similar as possible, such as in age, health status, or smoking habits.

Sample Size: The number of individuals or participants in a study. Larger sample sizes increase the statistical significance of results and the confidence that findings are not due to chance.
Case Example (Rats): The National Toxicology Program used a sample of $1,260$ rats to study cell phone radiation.
Small Samples: Studies with very small samples (e.g., $n=5$ or $n=10$ ) yield weak evidence that should be viewed with skepticism.

Epidemiology: The study of disease patterns in human populations, often utilizing case-control studies or randomized clinical trials.
Correlation vs. Causation: A correlation (a consistent relationship between two variables) does not prove that one variable causes the other.
Media Reports: Media headlines often simplify or exaggerate findings. Skeptical consumers should look for details on sample size, study design, and whether the research was peer-reviewed.
Recall Bias: A limitation in epidemiological studies where participants may not accurately remember past behaviors (e.g., past cell phone usage).

Experimental Assignment: In a study on Red Bull and memory, participants should be assigned to groups completely randomly to ensure validity.
Placebo Awareness: The control group should not know they are receiving a placebo to avoid the placebo effect.
Review of Study Reliability: If a news report claims cereal improves heart health based on a study of only $5$ individuals, the conclusion is unreliable due to the small sample size.
Sleep and Weight Loss Case: A study by Nedeltcheva et al. published in the Annals of Internal Medicine involved $10$ overweight individuals studied for $2$ weeks. The researchers found that while total weight loss was similar between groups getting $5.5$ and $8.5$ hours of sleep, those with less sleep lost more lean muscle and less body fat.